NATO Secretary-General Jens Stoltenberg on Monday called for China to face consequences for what US officials have called a major export push to rebuild Russia's defence industry.

China presents itself as a neutral party in the Ukraine war, and says it is not sending lethal assistance to either side, unlike the United States and other Western nations.

On Tuesday Beijing said that NATO "should engage in self-reflection rather than arbitrary smear and attacks on China".

"We advise (NATO) to stop shifting blame and sowing discord, not add fuel to the fire and instigate confrontation, but rather do something practical for the political settlement of the crisis," foreign ministry spokesman Lin Jian said at a regular press briefing.

China and Russia's strategic partnership has only grown closer since the invasion of Ukraine, but Beijing has rebuffed Western claims that it is aiding Moscow's war effort.

It has however offered a critical lifeline to Russia's isolated economy, with trade booming since the conflict began.

And G7 foreign ministers on Friday expressed "strong concern" about transfers of dual use materials and weapons components from Chinese businesses to Russia being used by Moscow for its military expansion.