WASHINGTON (AP) — US intelligence suggests China is considering providing arms and ammunition to Russia, an involvement in the Kremlin’s war effort that would be a “serious problem,” Secretary of State Antony Blinken said.

Blinken said the United States long has been concerned that China would provide weapons to Russia. He pointed to Chinese leader Xi Jinping’s promise to Russian President Vladimir Putin of a partnership with “no limits” when they met just weeks before Putin sent his troops into Ukraine on February 24, 2022. Since then, ties between the two countries have only grown stronger.

“We’ve been watching this very, very closely. And, for the most part, China has been engaged in providing rhetorical, political, diplomatic support to Russia, but we have information that gives us concern that they are considering providing lethal support to Russia in the war against Ukraine,” Blinken said in an interview that aired Sunday, a day after his meeting at a security conference in Munich with Wang Yi, the Chinese Communist Party’s most senior foreign policy official.

“It was important for me to share very clearly with Wang Yi that this would be a serious problem,” Blinken said.

With Putin determined to show some progress on the battlefield as the war nears the one-year mark, Russian forces have been on the offensive in eastern Ukraine.

“The Ukrainians are holding very strong, the Russians are suffering horrific losses in this effort,” Blinken said. He estimated that Russia has 97 per cent of its ground troops in Ukraine.

The Russians also are eager to capture more territory before Ukraine receives the more advanced weapons recently pledged by the US and its European allies.

“But what Secretary Blinken said is big news to me,” said Senator Lindsey Graham. Graham said the world should “come down hard on China” if it provides lethal weapons to Russia and he advised Chinese leaders not to do anything rash.

“To the Chinese, if you jump on the Putin train now, you’re dumber than dirt,” he said. “It would be like buying a ticket on the Titanic after you saw the movie. Don’t do this.”

Graham said it would be the “most catastrophic thing that could happen to the US-China relationship. … That would change everything forever.”

Tensions between Washington and Beijing have been heightened in recent weeks after the US shot down what it says was a Chinese spy balloon. China insists it was used mainly for meteorological research and was blown off course.

The US ambassador to the United Nations, Linda Thomas-Greenfield, also expressed her concern about any effort by the Chinese to arm Russia, saying “that would be a red line.”