With two months left in office, the president for the first time authorized the Ukrainian military to use the system known as ATACMS to help defend its forces in the Kursk region of Russia, The New York Times (NYT) reports.

US officials reportedly said that President Biden has authorized the first use of U.S.-supplied long-range missiles by Ukraine for strikes inside Russia.

The weapons are likely to be initially employed against Russian and North Korean troops in defense of Ukrainian forces in the Kursk region of western Russia, the officials said.

Mr. Biden’s decision is a major change in U.S. policy.  The choice has divided his advisers, and his shift comes two months before President-elect Donald J. Trump takes office, having vowed to limit further support for Ukraine.

Allowing the Ukrainians to use the long-range missiles, known as the Army Tactical Missile Systems, or ATACMS, came in response to Russia’s surprise decision to bring North Korean troops into the fight, officials said.

A US official reportedly confirmed the move, a major change of US policy, to the BBC's US partner CBS.

Reuters, citing two U.S. officials and a source familiar with the decision, reports that Ukraine plans to conduct its first long-range attacks in the coming days, the sources said, without revealing details due to operational security concerns.

Poland reportedly welcomed the decision of the United States

According to NYT, President Volodymyr Zelensky of Ukraine did not confirm the permission to strike but suggested on Sunday that more important than lifting the restrictions would be the number of missiles used to strike the Russians.

Russian President Vladimir Putin has previously warned Western nations against such a move, saying it would represent the NATO military alliance's “direct participation” in the Ukraine war.