The Kremlin on Wednesday accused Washington of "adding fuel to the fire" by planning to supply Ukraine with advanced missile systems.
"We believe that the United States is adding fuel to the fire deliberately and on purpose," Kremlin spokesman Dmitry Peskov told reporters.
"Such supplies" do not encourage Kyiv to resume peace talks, Peskov said, adding that Washington wanted to "fight Russia to the last Ukrainian."
On Tuesday, Washington said it would be supplying Ukraine with advanced missile systems, including the Himars multiple-launch rocket system that can simultaneously launch multiple precision-guided missiles.
Earlier Russian Deputy Foreign Minister Sergei Ryabkov said that the planned delivery of these new U.S. weapons to Ukraine increased the risk of drawing the United States into direct conflict with Russia.
"Any arms supplies that continue, are on the rise, increase the risks of such a development," Ryabkov was quoted as saying by state news agency RIA Novosti.
Both Ukraine and Russia already operate multiple-launch rockets systems, but the Himars have superior range and precision.
The Himars system that Washington is providing to Ukraine will have a range of about 80 kilometers (50 miles).
Ryabkov said the U.S. was determined to "wage war [on Moscow] to the last Ukrainian in order to inflict, as they say, a strategic defeat on Russia."
"This is unprecedented, this is dangerous," he said.