SEOUL, South Korea — Just three days after President Donald Trump sketched out an idea to meet with North Korea’s Kim Jong Un again, Kim responded by accepting a different kind of invitation — to Beijing, where he will join Russia’s Vladimir Putin and China’s Xi Jinping in a show of defiance against the Western-led global order.

Kim will be among the 26 heads of state attending China’s enormous Victory Day military parade next week to mark the 80th anniversary of the end of World War II, Beijing announced Thursday. Xi will showcase his efforts to modernize the People’s Liberation Army to counter the United States — complete with hundreds of increasingly high-tech tanks, missiles and anti-drone systems.

Kim has not been to China since 2019, and the parade could serve as further inspiration for the North Korean leader, who is pursuing a military upgrade of his own — with a considerable amount of help from Putin.

At the start of 2021, Kim announced a five-year plan to build more nuclear-capable weapons, a wish list that seemed far-fetched at the time. The leader of one of the world’s poorest countries aspired for some capabilities only a few major military powers had mastered.

With his January deadline fast approaching, analysts say, Kim has made surprising progress: He now has a credibly upgraded arsenal, even if many of the technologies are not quite ready to use.

Kim, it turns out, had impeccable timing. One year after announcing his goals, Russia launched a war against Ukraine - paving the way for a new era of friendship between Pyongyang and Moscow.

“I think most of the people who listened to his presentation [in 2021] said, ‘Maybe one or two of those things, but a whole bunch of them? Not likely,’ ” said Bruce Bennett, a North Korea military expert at Rand, a national security think tank. “Kim came a lot further than many people expected. I think the Russian help has been important.”

Wednesday’s parade will be Kim’s third time meeting with Putin since the Russian invasion of Ukraine in 2022, as the two leaders, both under heavy Western sanctions, unite in solidarity.

North Korea doesn’t have much the world wants, but it had plenty of the artillery that ammunition-hungry Russia needed and was willing to send thousands of troops into battle to help Putin’s war effort. Moscow is believed to be reciprocating with weapons technology and economic support.

Together, this means Kim doesn’t need the United States as it did in the decades it used its nuclear ambitions as a bargaining chip in negotiations with Washington.

That will make it much more difficult for Trump to reprise the relationship he tried to forge with Kim in his first term in pursuit of a denuclearization deal — despite the U.S. president’s praise for the North Korean leader this week.

Instead, a new concern is arising: As Kim grows increasingly confident in his growing nuclear arsenal and support from Putin, he may be willing to take more risks and provocations to get what he wants politically, particularly toward South Korea.

“In the future, if the North Koreans detect the right timing, they can really cause a huge amount of instability in the region,” said Go Myong-hyun, senior research fellow at Seoul’s Institute for National Security Strategy, a think tank affiliated with South Korea’s spy agency.

With Russia by its side, North Korea can now make rapid progress in areas that previously seemed out of reach. This makes North Korea — and its threats to the United States and its allies — more formidable than ever, Go said.

There’s still a lot that remains unknown about the North’s capabilities. Pyongyang has not tested a nuclear device since 2017 and, Vann H. Van Diepen, a former senior nonproliferation official at the State Department, said the results of weapons tests since 2021 have been a mixed bag or impossible to verify.

But experts warn that each failed launch gives Pyongyang a chance to learn from its mistakes and fix them. “They clearly want to show that they’ve got a diversified, and therefore survivable, force,” Van Diepen said, referring to North Korea’s ability to not only survive an attack but also to seriously retaliate with nuclear weapons.

What is even more certain, experts say, is Moscow’s assistance.

Since 2023, when Kim and Putin met at a cosmodrome in Russia’s Far East in a public display of transactional affection, North Korea already appears to have received air defense systems and antiaircraft missiles from Russia — much-needed upgrades to North Korea’s antiquated air force.

“What we need to be extremely wary of is whether North Korea’s technology advances explosively with Russia’s help,” said Yang Uk, a North Korean military expert at the Asan Institute for Policy Studies in Seoul. “That would lead to a proliferation of technology that we can’t roll back.”

Here are some of the developments North Korea has made since Kim laid out his ambitious plans in 2021.

A range of nuclear warheads

For more than a decade, North Korea has been working to make nuclear warheads small enough to fit on top of a missile.

In March 2023, Pyongyang unveiled the Hwasan-31, a tactical nuclear warhead. It was only 18 inches in diameter, suggesting the North was making progress on miniaturization, according to the Open Nuclear Network, an NGO that analyzes nuclear risks.

It hasn’t tested this small warhead by detonating it. Nor has it proved that it has mastered the difficult reentry technology that would enable the warhead-tipped missile to withstand the extreme heat and vibrations involved with coming back into the Earth’s atmosphere and delivering the warhead to a target.

Kim also wants to complete the development of a “superlarge” hydrogen bomb, which is far more destructive than atomic bombs, but the status of this project is unknown.

His regime last carried out a nuclear test in 2017, detonating what it said was a hydrogen bomb. The explosion was recorded as a 6.3-magnitude earthquake, lending credibility to North Korea’s claims.

But Pyongyang has not pressed ahead with nuclear tests, perhaps because of warnings from China, the North’s main trading partner, experts say.

The regime does, however, appear to have continued producing weapons-grade uranium. North Korea last year released photos of Kim visiting a uranium-enrichment facility, underscoring his growing nuclear ambitions.

Multiple warheads on one missile

One area where North Korea has made clear and demonstrable progress is in missiles. Over the past four years, it has fired intercontinental ballistic missiles that can reach the mainland U.S., as well as “tactical” ones that fly shorter distances and could be used to strike nearby South Korea and Japan.

In 2023, it successfully launched a military reconnaissance satellite into orbit after two failed tests — a capability it has long sought, and which Putin publicly said he’d help it develop.

Now, Kim wants to develop multiple independently targetable reentry vehicles (MIRV), which would allow a single missile to direct several nuclear warheads to different targets.

This is challenging technology, but it could overwhelm the missile defense systems of the United States and its allies because they have to deal with missiles being launched at multiple locations at the same time, experts say.

A test in June last year showed North Korea is serious about developing multiple-warhead missiles: The regime fired an intermediate-range ballistic missile with what it claimed were three independently targeted warheads and a decoy. The South Korean military found the booster most likely failed after launch, exploding midair and scattering into pieces, but Van Diepen wrote that Kim clearly thought he was making enough progress to warrant a flight test.

North Korea is likely to continue testing this technology, and help from Russia could significantly speed up its progress, experts say.

Nuclear-powered submarine

In March, Pyongyang revealed images of the hull of what it claimed was its first nuclear-powered submarine underway, one of Kim’s priorities under his five-year plan.

A nuclear-powered submarine, which can stay underwater far longer than a diesel-powered one, would be an impressive feat.

But such a submarine is expensive and requires highly sophisticated technology, including a nuclear reactor inside the vessel. North Korea is likely years away from being operational, experts say. In fact, only six countries have mastered it. One of them is Russia — and many experts said Moscow may be willing to lend a hand.

Lami Kim, an international security expert at the Daniel K. Inouye Asia-Pacific Center for Security Studies in Honolulu, said the Putin-Kim friendship could be a game changer: “Now, with Russia’s support, I think it is actually possible that North Korea will be able to build them.”

There’s precedent: In the 1980s, the former Soviet Union helped India, which launched its first nuclear-powered ballistic missile submarine in 2009.

Hypersonic glide vehicle

North Korea has been developing hypersonic weapons, which travel at least five times the speed of sound and at low altitudes, and are difficult to track and intercept. They are also much easier to maneuver than traditional ballistic missiles.

This cutting-edge technology is being developed by major military powers — including China, Russia and the United States — and since 2021, North Korea has tested several of what it claimed were hypersonic missiles.

The next step is for North Korea to successfully launch a hypersonic glide vehicle (HGV), which even the world’s best militaries are competing to master. They are highly maneuverable after they are released from their rocket boosters — and therefore harder to shoot down.

Kim appears to be making some headway. In January, North Korea tested the Hwasong-16B, a new type of intermediate-range ballistic missile, which could reach Guam and the Philippines. Pyongyang said it successfully test-fired the missile, which flew more than 930 miles at 12 times the speed of sound. Seoul called the distance estimate a “deception,” though its former defense minister said the North is making progress and “will succeed one day” given how much it has prioritized the project.

Drones

Kim has already demonstrated a variety of reconnaissance drones under his plan, which allow North Korea to surveil and collect sensitive information on South Korean forces and facilities.

North Korea’s drone capabilities are developing rapidly, while Seoul’s drone strategy has been woefully lagging, said Lami Kim, the international security expert — leaving South Korea potentially vulnerable to a threat responsible for extensive carnage in Ukraine and elsewhere.

Meanwhile, North Korea has gained experience in confronting Ukrainian drones. It’s not only using drones to spy, but it is also producing ones that can strike, including by carrying GPS-guided bombs.

Russia and North Korea are even cooperating on the production of the Geran drone, a Russian version of the Iranian-made Shahed, according to the Ukrainian intelligence agency.

Russian instructors are working in North Korea and training North Korean drone pilots, according to a Telegram post in July by Andriy Kovalenko, head of the Ukrainian National Security and Defense Council’s Center for Countering Disinformation.