China bears responsibility for using its influence on Russian President Vladimir Putin to end the war in Ukraine, U.S. Secretary of State Antony Blinken said.

His remarks came ahead of U.S. President Joe Biden's phone call with Xi Jinping.

"We continue to call on all nations, especially those with direct influence with Russia, to use whatever leverage they have to compel Moscow to end this war of choice. We believe China in particular has a responsibility to use its influence with President Putin and to defend the international rules and principles that it professes to support," Blinken said.

"Instead, it appears that China is moving in the opposite direction by refusing to condemn this aggression while seeking to portray itself as a neutral arbiter. And we're concerned that they're considering directly assisting Russia with military equipment to use in Ukraine. President Biden will be speaking to President Xi tomorrow and will make clear that China will bear responsibility for any actions it takes to support Russia's aggression and we will not hesitate to impose costs," he said.