KYIV — Ukraine’s security services said Friday they have uncovered a Hungarian spy ring that was gathering information about Ukrainian military operations in the far west of the country.

The alleged network was collecting information on air and ground defense vulnerabilities in Ukraine’s Transcarpathia region as well as local sentiment on a potential invasion by Hungary, the Ukrainian statement said.

“For the first time in the history of Ukraine, the Security Service has exposed a Hungarian military intelligence agent network that was carrying out espionage activities to the detriment of our state,” it said.

Ukraine’s Transcarpathian region borders Hungary and is home to a Hungarian minority. Over the last decade, Hungary has maintained that Kyiv is limiting the cultural and linguistic rights of the Hungarian population, and some Hungarian lawmakers have talked publicly about annexing the region.

The spies were also tasked with establishing the extent of law enforcement activity in the region and assessing how well-equipped such units are, Kyiv said.

In response to the announcement by Ukraine, Hungarian Foreign Minister Peter Szijjarto expelled two Ukrainian diplomats whom he in turn accused of spying under diplomatic cover. He added that Budapest would not tolerate “smear campaigns against Hungarians.” Szijjarto also said Hungary has not received any official information from Ukraine on the matter.

“It is clear that anti-Hungarian propaganda is often used in Ukraine. Anti-Hungarian propaganda that in many cases has turned out to be completely unfounded,” he said.

One of the two agents detained by Ukraine’s security services was recruited in 2021 and put on standby, according to the statement. The agent was then activated in September 2024.

The agent tried to recruit others and establish a network that Hungarian military intelligence hoped would expand to include other regions in Ukraine, including front-line areas. Ukraine said. Hungarian military intelligence supplied the agent with cash and a phone with special software that could be used for covert communication, it said.

Hungarian Prime Minister Viktor Orban has made no secret of his admiration for Russian President Vladimir Putin and his disdain for the Ukrainian cause. Since Russia invaded Ukraine in 2022, Orban’s government has often thwarted or delayed European Union initiatives to help finance Ukraine or sanction Russia. Hungary has also been one of the few Western countries that has refused to supply weapons to Ukraine.

Ukraine’s allegations are particularly controversial given Hungary’s membership of NATO and the European Union — two organizations that consider themselves Ukraine’s biggest supporters and partners.

Ukraine’s security services said the alleged spies could face life imprisonment if found guilty and that authorities are working to uncover all participants in the ring. Ukraine said it has also identified the Hungarian military intelligence staffer who was in charge of the agents.