China has refused to supply Russian airlines with aircraft components. “We have instructed the airlines to determine themselves where it is possible to purchase these spare parts. As far as I know, they [the airlines] turned to China, but the Chinese refused, ” Valery Kudinov, head of Airworthiness Maintenance Department of the Russian Federal Air Transport Agency, told reporters on the sidelines of the MRO Russia & CIS conference.

https://www.uawire.org/china-refuses-to-supply-aircraft-components-to-russian-airlines

Maybe if Russia returns Yongmingcheng (i.e. Vladivostok) to the Chinese, they’ll change their minds.