A White House official on Friday confirmed that Russia has sent a formal diplomatic note to the United States saying weapons shipped to Ukraine from the U.S. and NATO were "adding fuel" to the conflict.
The note, reported by The Washington Post, said deliveries of the "most sensitive weapons" could result in "unpredictable consequences" for the U.S.
Biden on Wednesday authorized an additional $800 million in weapons for Ukraine.
Drone footage form Mariupol, Ukraine, shows a destroyed apartment building.
Get Tri-state area news delivered to your inbox.> Sign up for NBC New York's News Headlines newsletter.
For more on this story, go to NBC News.
This is a live update. Click here for complete coverage of the crisis in Ukraine.
