Seoul, Dec 19 (IANS): North Korean troops dispatched to Russia for combat against Ukraine have installed more observation posts to detect Ukrainian drones, Ukraine's military intelligence service has said, amid reports of North Korean forces suffering heavy combat losses.

The Defence Intelligence of Ukraine (DIU) made the disclosure on its website Tuesday after the United States confirmed for the first time that North Korea suffered 'significant' troop losses alongside Russian forces against Ukraine.

"After suffering severe losses, DPRK units began to set up additional observation posts to detect drones of the Security and Defense Forces of Ukraine," the DIU said, referring to the North by the acronym of its official name -- the Democratic People's Republic of Korea.

The DIU also noted that Moscow continued to use North Korean troops in Russia's western front-line region of Kursk.

"The constant accumulation of assault groups by DPRK army personnel in the Kursk region indicates that Moscow does not want to lose the pace of offensive actions," it said, adding that North Korean troops use red tape to identify themselves at the front, Yonhap news agency reported.

On Thursday, South Korea's spy agency told lawmakers that at least 100 North Korean troops dispatched to Russia have been killed, with some 1,000 estimated to be injured.

The National Intelligence Service attributed the high number of casualties to the fact that North Korean troops are being 'consumed' as front-line assault forces in 'unfamiliar battlefields' due to their lack of experience with drones.

It added that Russia's military has complained that the North Korean soldiers are a 'burden' because of their 'ignorance' of drones.

Some of the estimated 11,000 North Korean soldiers deployed in the Kursk border region were sent into actual combat, according to the NIS.

"At least 100 people have been killed in this process, and the number of injured is likely to reach 1,000," the agency said, noting that generals were likely included among the casualties.

The NIS attributed the high number of casualties to the fact that North Korean troops are being 'consumed' as front-line storm troopers in 'unfamiliar battlefields' due to their lack of experience with drones.