Russia asked China to give it military equipment and support for the war in Ukraine after President Vladimir V. Putin began a full-scale invasion last month, according to U.S. officials.

Russia has also asked China for additional economic assistance, to help counteract the battering its economy has taken from broad sanctions imposed by the United States and European and Asian nations, according to an official.

American officials, determined to keep secret their means of collecting the intelligence on Russia’s requests, declined to describe further the kind of military weapons or aid that Moscow is seeking. The officials also declined to discuss any reaction by China to the requests…

The Biden administration is seeking to lay out for China the consequences of its alignment with Russia and penalties it will incur if it continues or increases its support. Some U.S. officials argue it might be possible to dissuade Beijing from ramping up its assistance to Moscow. Chinese leaders may be content to offer rhetorical support for Moscow and may not want to further enmesh themselves with Mr. Putin by providing military support for the war, those U.S. officials say.