Russia has criticized US plans to send more advanced artillery systems to Ukraine, accusing Washington of “adding fuel to the fire”.
President Biden announced the move earlier, but played down fears of a direct Nato-Russia conflict.
Biden said the goal was to help Ukraine defend itself and that Washington was not encouraging Ukraine to strike beyond its borders.
Meanwhile, an official in the key eastern city of Severodonetsk says Ukrainian forces now only control 20 percent of territory there.
While Russia targets its efforts on the east, President Volodymyr Zelensky says Ukraine is making advances in battlegrounds elsewhere in the country.