Moscow has warned Washington that its decision to send more military aid to Ukraine “increases the risk of a direct military clash” between Russia and the West.
Russia’s ambassador to the United States, Anatoly Antonov, said this represented a “direct threat” to Moscow, describing the United States as a “partner in the conflict.”
The United States had earlier announced the allocation of $625 million in additional military aid to Ukraine.
Advanced US weaponry is credited with helping Ukraine keep its pace with Russia’s occupying forces.
Ukrainian forces have made significant progress in the north-east and south of the country in recent weeks.
State-of-the-art US equipment includes four HIMARS high-precision multiple missile systems.
Washington has so far committed nearly $17 billion in military support to Kiev since Russian President Vladimir Putin invaded Ukraine on February 24.
In a statement issued on Thursday, Antonov warned that the US decision “to continue supplying the Kyiv regime with heavy weapons only confirms Washington’s status as a partner in the conflict.”
This will lead to “longer bloodshed and new losses,” he said.
The Russian ambassador said: “We call on Washington to stop its provocations, which may lead to the most serious consequences.”
Having suffered a series of major battlefield defeats in Ukraine in recent weeks, Russia has vowed to defend itself by all available means – without ruling out the use of its nuclear weapons.
Moscow is still moving forward with its attempts to annex four regions in Ukraine: Donetsk and Luhansk in the east, and Kherson and Zaporizhia in the south.
But it does not fully control any of those areas, and Ukrainian forces have made rapid advances in the Kherson region in recent days.
Antonov’s warning comes shortly after US President Joe Biden and Vice President Kamala Harris discussed more military cooperation with Ukrainian President Volodymyr Zelensky.
The White House stressed in a statement that “the United States will never recognize Russia’s alleged annexation of Ukrainian territory.”
Biden pledged to continue supporting Ukraine as it defends itself against Russian aggression for as long as it takes.
The statement said the new military aid package included “(the) Haymars, artillery systems, ammunition and armored vehicles.”
US-made Hymars systems, which are highly mobile artillery rockets, have been used to strike Russian targets, including command posts and ammunition depots.
It was also used to target bridges, some of which are close to Kherson, which is occupied by Russia and which Ukraine is trying to retake.