The six months since Washington hosted an African trade conference have seen a notable bump in business with the continent and a troubling deterioration in relations with its top continental trading partner.

President Biden's U.S.-Africa Leaders Summit in December resulted in $15.7 billion in trade agreements between American companies and African countries and companies, diplomat Johnnie Carson told an international video news conference Tuesday. "Since then, the number of deals has actually increased to $16.2 billion," said Carson, the special presidential representative for summit implementation.

Since December, the Biden administration has demonstrated its commitment to Africa with nine trips by senior officials, "an unprecedented number of high-level visits to the continent," added National Security Council Senior Director for African Affairs Judd Devermont, "and of course it will be culminated with a trip by President Biden."

But now, the U.S. relationship with one of its major continental partners, South Africa, is pained because of its business with Russia.

The latest manifestation of that was a bipartisan letter last week from congressional leaders urging Biden to move a planned U.S.-led trade forum from South Africa and questioning its eligibility for continued inclusion in the African Growth and Opportunity Act (AGOA), which includes broad duty-free access to American markets and, as the legislators said, "is the cornerstone of the United States economic relationship with sub-Saharan Africa."

The letter writers are an influential group, with all but one of the Democratic and Republican leaders of the Senate and House committees on foreign matters. The first signature on the letter is Sen. Christopher A. Coons (D-Del.), chairman of the Senate Appropriations subcommittee on foreign operations. But, equally important, he is known for his close relationship with his most prominent constituent - President Biden.

Other signers were Rep. Michael McCaul (R-Tex.), House Foreign Affairs Committee chairman; Rep. Gregory W. Meeks (D-N.Y.), the ranking Democrat on the House panel; and Sen. James E. Risch (R-Idaho) the top Republican on the Senate Foreign Relations Committee. Notably missing from the letter was Sen. Robert Menendez (D-N.J.), chairman of the Senate committee.

The letter complained that despite being formally neutral on Russia's invasion of Ukraine, South Africa "has deepened its military relationship with Russia over the past year."

According to the letter, intelligence suggests that the South African government covertly supplied arms and ammunition to a Russian cargo vessel subject to U.S. sanctions that docked in its largest port last year. South Africa also held joint military exercises with Russian and China in February. Two months later, a South African air force base hosted a Russian military cargo plane, which also faces U.S. sanctions.

"On top of this, in August, South Africa will host the BRICS (Brazil, Russia, India, China, and South Africa) Summit where the government aims to strengthen its ties with China and Russia and is working to facilitate the participation of Russian President Vladimir Putin, despite the outstanding arrest warrant issued by the International Criminal Court (ICC)," the letter adds.

South African officials in Pretoria and Washington could not be reached for comment.

Mkhuseli "Khusta" Jack, who fought the country's racist rule and now is a Nelson Mandela Bay Municipality council member, said "the majority of people here will be badly hurt" if Washington downgrades economic ties to South Africa. But the United States could be hurt too, financially and with declining Africa influence, as competition from BRICS countries grows. U.S. trade with its largest African trading partner, South Africa, totaled $24.5 billion in 2021, according to the Office of the U.S. Trade Representative. Imports were more than two-thirds of that, $16.8 billion.

While Jack supports strong U.S. involvement in South Africa, he said by video call that "even people like me will always feel affection for the Soviet Union because of its stance at the time when the West was totally opposed to us fighting against apartheid. But the current Russia is no Soviet Union. It's something completely different."

Washington has no right to dictate Pretoria's foreign policy, but the congressmen cited AGOA's requirement that beneficiary countries "not engage in activities that undermine United States ... foreign policy interests."

Yet, the activities the letter cites include the unproven allegation about South African covert arms supply to Russia and a visit by Putin that hasn't happened yet. It's also ironic that the congressional leaders cite the international court warrant when the United States has rejected membership in the court.

That leaves the joint military exercises and the landing of a Russian cargo plane. Is that enough to disrupt what has been a generally close relationship with an important regional leader?

Meeks described the letter, in a phone interview, as "leverage," or a warning about possible U.S. repercussions if Pretoria gets too cozy with Moscow as it wages war on Ukraine. "It's trying to get them to do a course correction," he said. "It would be damaging to them if Putin would show up in Johannesburg for the BRICS conference."

Molly Phee, the assistant secretary of state for Africa, pointedly noted Washington's "expectation that the South African Government will adhere" to its policy of nonalignment.

South Africans are divided on issues involving the United States and Russia, explained Rich Mkhondo, a South African political commentator. There is an affinity for America and its many companies providing jobs, goods and services in South Africa. Yet they reject U.S. hypocrisy, he added in a phone interview from Durbin, South Africa, that allows U.S. officials to "criticize people who support Russia's atrocities, while they've also committed atrocities around the world."

Bob Wekesa, deputy director of the African Center for the Study of the United States at the University of the Witwatersrand in Johannesburg, called the congressional letter "an escalation of tensions" and warned that "a hard stance by the United States might hasten South Africa's embrace of Russia and the BRICS." This year, Wekesa is a visiting fellow at the University of Southern California's Washington campus. Moving the AGOA forum from South Africa would "embolden those who do want to see the government align more closely with Russia and China," said Krista Johnson, director of the Howard University Center for African Studies.

Yet even if Washington excludes Pretoria from AGOA, other bilateral activities will continue and both sides will get over this, predicted Melvin P. Foote, president and CEO of Constituency for Africa.

"I don't think the U.S. wants to dump South Africa," Foote said, "and I don't think South Africa wants to dump the United States."