Biden vows air defence systems for Ukraine

"President Biden pledged to continue providing Ukraine with the support needed to defend itself, including advanced air defence systems," a White House statement said.

Biden also told Zelenskiy the United States and its allies and partners would continue imposing costs on Russia, "holding Russia accountable for its war crimes and atrocities, and providing Ukraine with security, economic, and humanitarian assistance", the White House said on Monday.

The United States has provided more than $US16.8 billion ($A27 billion) worth of US security assistance since Russia invaded Ukraine on February 24 and imposed a wide-ranging array of economic sanctions on Moscow over its actions in Ukraine.