South Korea's intelligence agency says North Korean troops sent to Russia have been assigned to Russia's airborne brigade and marine corps, with some of them having already entered combat against Ukrainian forces.

The National Intelligence Service on Wednesday presented to the parliamentary Intelligence Committee its latest assessment on these North Korean troops. The soldiers are reported to be deployed to Russia amid Moscow's ongoing invasion of Ukraine.

Lawmakers who attended the parliamentary session cited agency officials as saying about 11,000 North Korean troops were relocated to the western Russian region of Kursk in late October after completing training in the northeast of the country.

The agency officials were also quoted as saying the troops have been assigned to Russia's airborne brigade or marine corps on the ground, with some undergoing training in tactics and drone response.

The report says other troops have already entered combat, and they may have suffered casualties.

The officials added they are trying to determine the extent of the damage and other details.

The agency also told the lawmakers that North Korea has exported long-range artillery to Russia, including self-propelled howitzers and 240-millimeter multiple rocket launchers, in addition to previously reported shipments of artillery shells and missiles.

The lawmakers said the intelligence officials suggested the possibility of North Korean leader Kim Jong Un visiting Russia.

The South's intelligence agency is also reported to be closely monitoring the possible transfer of weapons and military technology from Russia to the North.