Leading American media outlets report that President Joe Biden has authorized the Ukrainian military to use US-supplied long-range missiles to strike targets inside Russia.

The news organizations quoted US officials on Sunday as saying the authorization concerns the use of weapons known as the Army Tactical Missile Systems, or ATACMS. The missiles are reportedly capable of precision strikes.

The New York Times quotes officials as saying the authorization "came in response to Russia's surprise decision to bring North Korean troops into the fight."

It also cites officials as saying 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." Ukrainian forces have been engaging in a cross-border incursion in the region.

The New York Times says "Biden's decision is a major change in U.S. policy." It adds that 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."

Ukraine had repeatedly asked the US to allow it to hit inside Russia with long-range missiles provided by the Biden administration. But Washington had refused to give the green light out of concern that such strikes would sharply escalate tension.