Russia says the United States' decision to ship more weapons to Ukraine poses an "immediate threat" to Moscow's interests and hikes the risk of a direct military confrontation between Russia and the West.
"The supply of military products by the US and its allies not only entails protracted bloodshed and new casualties, but also increases the danger of a direct military clash between Russia and Western countries," Russia's Ambassador to the US Anatoly Antonov said on the Telegram messaging app on Wednesday.
"We perceive this as an immediate threat to the strategic interests of our country," he said, after US President Joe Biden pledged a new $625-million military aid package to Ukraine on Tuesday.
The US package would include High Mobility Artillery Rocket System (HIMARS) launchers, reportedly used in Ukraine's recent counter-offensives against Russian forces, leading to their withdrawal.
Last week, Washington also unveiled a $1.1-billion arms package for Ukraine, which included 18 HIMARS launcher systems, accompanying munitions, various types of counter drone systems and radar systems.
But last week's weapons package was funded by the Ukraine Security Assistance Initiative (USAI), meaning the government has to procure the weapons from industry, rather than pulling them from existing US weapons stocks.
The latest announcement would mark more than $16.8 billion worth of US security military aid to Kiev since Russia began what it calls a "special military operation" in Ukraine back in February, citing the failure of the US-led NATO military alliance and Kiev to offer Moscow security guarantees it sought in connection with NATO's eastward expansion.
The aid package is the first since the accession to Russian Federation of four former Ukrainian territories — namely Donetsk, Luhansk, Kherson, and Zaporizhzhia — after holding referendums that Russia said overwhelmingly favored the move.
In a strongly-worded response, Russia's US envoy warned Washington to stop "provocative actions" that could lead to "serious consequences," saying that the move fueled the risk of a war between Russia and the West.
Moscow's warning also came after US Secretary of State Antony Blinken issued a statement claiming, "Recent developments from Russia's sham referenda and attempted annexation to new revelations of brutality against civilians in Ukrainian territory formerly controlled by Russia only strengthens our resolve."
US boosts arms aid as Ukraine expands battle gains
The US move to send more weapons to Ukraine also comes as Kiev claimed sweeping gains along two major battlefronts in an offensive rush to beat the arrival of fresh Russian troops.
Ukrainian President Volodymyr Zelensky claimed on Tuesday that his forces were making "rapid and powerful" gains and had retaken "dozens" of villages from Russia this week in the east and south.
Zelensky said eight settlements in the southern Kherson region, where Moscow's forces have withdrawn from, have been retaken.
In a briefing in Moscow, the Russian military conceded in updated maps of the fronts that they had incurred significant territorial losses. The latest battlefield maps from Moscow showed that Russian troops had left many areas in Kherson, including along the west bank of the Dnipro River.
In the eastern Kharkiv region, the maps indicated that Russian forces had almost entirely abandoned the east bank of the Oskil River, potentially giving the Ukrainians space to shell key Russian troop transportation and supply corridors.
"Our soldiers do not stop. And it's only a matter of time before we expel the occupier from all of our land," Zelensky said.
Russia, meanwhile, pushed ahead with its rapid-fire mobilization of more troops to shore up those already fighting in Ukraine.
The World Bank, meanwhile, announced that Ukraine's economy could shrink 35 percent this year, as the persisting conflict has forced more than 14 million people from their homes and stifled industrial production.
Ukraine's Central Bank Chief Kyrylo Shevchenko announced on Tuesday that he was stepping down for health reasons, saying, "The war was yet another difficult test for our team and for me personally."