US Secretary of State Antony Blinken has warned China that there will be "consequences" if it provides support to Russia in the Ukraine war.
Blinken has claimed that Chinese firms have already been providing "non-lethal support" to Moscow and new information suggests that "lethal support" can be provided.
He told CBS News after meeting China's top diplomat Wang Yi at the Munich Security Conference at the weekend: "To date, we have seen Chinese companies... provide non-lethal support to Russia for use in Ukraine. The concern that we have now is based on information we have that they're considering providing lethal support."
Blinken did not elaborate on the information that the US had received about China's potential plans but suggested that Beijing could provide Russia with weapons and ammunition.
China said that the claims were false and accused Washington of spreading lies.
Foreign ministry spokesman Wang Wenbin said: "We do not accept the United States' finger-pointing on China-Russia relations, let alone coercion and pressure."
Chinese President Xi Jinping is an ally of Russian leader Vladimir Putin and hasn't condemned the invasion of Ukraine but has sought to remain neutral in the conflict and has called for peace.
Republican senator Lindsay Graham warned that US-Chinese relations would deteriorate severely if Beijing were to deliver weapons to help Russian troops.
He told ABC News: "It would be like buying a ticket on the Titanic after you saw the movie. Don't do this."