Beijing has trod a cautious line on Ukraine as Moscow has massed thousands of troops on the borders, and criticised the West for new sanctions after Russia ordered troops into two breakaway Ukrainian regions it now recognises as independent.

US President Joe Biden earlier stressed that the penalties were only a "first tranche", adding that more sanctions would come if Russian President Vladimir Putin extended his country's military grip beyond the two territories in the eastern Donbas region.

China lashed out at Washington over the sanctions on Wednesday and said it was raising tensions by sending weapons to Ukraine.

The US actions were "raising tensions, creating panic, and even playing up the schedule of war," foreign ministry spokeswoman Hua Chunying told reporters.

"If someone is adding fuel to the fire while blaming others ... then that behaviour is irresponsible and immoral," she added, turning the spotlight on the United States in response to a question on China's role in resolving the situation.

She said China had "called on all parties to respect and attach importance to each other's legitimate security concerns, strive to resolve issues through negotiation and consultation, and jointly maintain regional peace and stability."

Asked if China would impose sanctions on Russia, Hua added that Beijing believes "sanctions have never been a fundamental and effective way to solve problems".

Apart from the United States, Britain, the European Union, Japan and Australia also announced penalties following Putin's decision to send soldiers into Donetsk and Lugansk.

On Tuesday, Biden said Washington would continue to supply "defensive" weapons to Ukraine against a Russian invasion, and deploy US troops to reinforce NATO allies in Eastern Europe.

"Let me be clear, these are totally defensive moves on our part," Biden said in a televised speech at the White House.