In an interview with CNN, U.S. Ambassador to the UN Linda Thomas-Greenfield said "that would be a red line" if China provided lethal aid to Russia.
"We welcome the Chinese announcement that they want peace because that’s what we always want to pursue in situations like this," she said. "But we also have to be clear that if there are any thoughts and efforts by the Chinese and others to provide lethal support to the Russians in their brutal attack against Ukraine, that that is unacceptable."
U.S. Secretary of State Antony Blinken said on Feb. 18 that Washington has concerns that Beijing is considering supplying Moscow with "lethal support," such as weaponry.
According to Blinken, the U.S. has already seen Chinese companies providing non-lethal support to Russia.
Blinken warned top Chinese diplomat Wang Yi that supplying weapons to Russia "would have serious consequences in our relationship."