President Biden announced that the United States will send Ukraine more advanced rocket systems to assist it in defending itself.
The weapons, which Ukraine has long sought, will allow it to strike enemy forces more precisely from a greater distance.
Until now, the US had refused the request out of concern that the weapons could be used against Russian targets.
Dmitry Peskov, a Kremlin spokesman, said the US was “directly and intentionally adding fuel to the fire” with its weapons deliveries to Ukraine.
Separately, the German government has promised to send Ukraine an air defence system.
Chancellor Olaf Scholz told MPs that the IRIS-T system was the most modern Germany possessed and would enable Ukraine to defend an entire city against Russian air attacks.
He added that he would provide tracking radar capable of detecting enemy artillery, and multiple rocket launchers.
Mr. Biden stated on Wednesday that the lethal aid would strengthen Kiev’s negotiating position against Russia and increase the likelihood of a diplomatic solution.
“That is why I’ve decided that we will provide the Ukrainians with more advanced rocket systems and munitions that will enable them to more precisely strike key targets on the battlefield in Ukraine,” he wrote in the New York Times.
This is a delicate balancing act for Mr. Biden, as providing more powerful weapons may provoke a reaction from Russia, potentially resulting in direct conflict between the US and its Nato allies and Moscow.
According to a senior White House official, new weaponry will include the M142 High Mobility Artillery Rocket System (HIMARS), though he did not specify how many would be supplied.