Beijing on Thursday said it would take "necessary measures" after the United States announced fresh sanctions aimed at crippling Russia's military and industrial capabilities, punishing companies in China and elsewhere that help Moscow acquire weapons for its war in Ukraine.

"The Chinese side urges the US to stop smearing and containing China and stop wantonly implementing illegal and unilateral sanctions," a foreign ministry spokesman said in a message to AFP.

"China will take all necessary measures to resolutely uphold the legal rights and interests of Chinese companies," he added.

In a sweeping package announced by the US Treasury Department on Wednesday, Washington targeted nearly 300 entities in Russia, China and other countries accused of supporting President Vladimir Putin's invasion.

Treasury Secretary Janet Yellen said her department had "consistently warned that companies will face significant consequences for providing material support for Russia's war", and that its "actions will further disrupt and degrade Russia's war efforts".

China has never condemned Russia's attack on Kyiv, and stands accused of indirectly supporting the war through its strategic partnership with its neighbour Moscow.

Beijing insisted again on Thursday it was "neither a creator nor a party" to the crisis in Ukraine, and said it had the right to develop "normal" trading relations with all countries, including Russia.

"China has always resolutely opposed the United States implementing illegal and unilateral sanctions against Chinese enterprises and exercising 'long-arm jurisdiction'," the spokesman said.