Two months after warning that Beijing appeared poised to help Russia in its fight against Ukraine, senior US officials say they have not detected overt Chinese military and economic support.

US officials told Reuters they remain wary about China's long-standing support for Russia in general, but that the military and economic support that they worried about has not come to pass, at least for now.

This comes as President Joe Biden prepares for a trip to Asia later this month and his administration is set to release his first national security strategy about the emergence of China as a great power.

"We have not seen the PRC provide direct military support to Russia’s war on Ukraine or engage in systematic efforts to help Russia evade our sanctions," a Biden administration official told Reuters, referring to the People's Republic of China.

"We continue to monitor for the PRC and any other country that might provide support to Russia or otherwise evade US and partner sanctions."

As well as steering clear of directly backing Russia's war effort, China has avoided entering new contracts between its state oil refiners and Russia, despite steep discounts. In March, the state-run Sinopec Group suspended talks about a major petrochemical investment and a gas marketing venture in Russia. (Reuters)