American officials are condemning China for what they say is a concerted effort to boost Russia's military assaults on Ukraine.

The boosted support comes as Ukraine is flailing and its power plants pounded as the U.S. Congress debates continued funding for the beleaguered nation.

China, meanwhile, is providing Russia with drone and missile technology, satellite imagery and machine tools, according to senior U.S. officials, Reuters reported. 

The Chinese Embassy in the U.S., however, insisted it has not provided weaponry to any party, Reuters noted. It emphasized that is "not a producer of or party involved in the Ukraine crisis." 

Sources told Reuters that President Biden raised the issue with Chinese President Xi Jinping in their recent phone call, and that other Ukraine allies have also complained. 

Ukraine is increasingly struggling for its existence. Russian airstrikes on Friday destroyed Kyiv's largest power plant.