Russia warns of 'fatal consequences' over U.S. weapon use in Ukraine war

June 3 (UPI) -- The Kremlin on Monday gave a stark warning against the use of U.S.-provided weapons by Ukraine to hit targets inside Russia in moves that have the potential to further escalate the ongoing eastern European military conflict.

"I would like to warn American leaders against miscalculations that could have fatal consequences," Russian Deputy Foreign Minister Sergei Ryabkov said Monday.

The Biden administration last week lifted a ban on Ukraine firing U.S. weapons into Russian territory but still are barred from mounting strikes deeper into Russia using the U.S.-made weapons.

President Joe Biden directed U.S. officials "to ensure that Ukraine is able to use U.S.-supplied weapons for counter-fire purposes in the Kharkiv region, so Ukraine can hit back against Russian forces that are attacking them -- or preparing to attack them," a U.S. official confirmed at the time.

"For unknown reasons, [American leaders] underestimate the seriousness of the rebuff they may receive," the Kremlin spokesperson added.

Russia in May had claimed captured territory after attacks in northeast Ukraine when Russian military forces launched a series of assaults on the region around the northeast city of Kharkiv, Ukraine's second-largest city, leading to thousands of evacuations from the area.

At the time, Russian officials claimed to have captured five villages near the Ukrainian town of Vovchansk, which sits just 3.7 miles from the border with Russia.

Following Biden's policy change, Germany likewise switched its stance on weapons-use given by them to Ukraine in a move that echoed their American counterparts.

Ukraine had over the last few weeks asked the United States for authorization to use weapons "that we're providing to defend against this aggression, including against Russian forces that are amassing on the Russian side of the border and then attacking into Ukraine," Secretary of State Antony Blinken said last week, adding how Biden "approved the use of our weapons for that purpose."

Last week in Sweden, Ukraine's President Volodymyr Zelensky acknowledged as much during a press conference

The removal of the ban on the use of U.S. arms gives Ukrainian commanders in Kharkiv province, near the border with Russia, clearance to counterattack Russian forces just over the border including preemptive strikes.