China is too strong to be bullied into siding with the US against Russia and will trade with whoever it wishes to, in accordance with international law. Just as the US and Nato can decide to provide military assistance to Ukraine, any other sovereign state can do the same for Russia if it chooses to.
The strained relationship between the US and Russia has not prevented Joe Biden from meeting Vladimir Putin. However, China can’t trust diplomatic efforts by a US administration that is intent on confronting and containing it.