South Korean Ambassador to the U.N. Hwang Joon-kook speaks during a U.N. Security Council session. Courtesy of U.N. Web TV.

South Korea's top envoy to the United Nations said Thursday that North Korean troops are being dissipated as "expendables" in Russia's war against Ukraine and treated as a "cynical" means of sustaining the North Korean regime.

During a U.N. Security Council meeting, Ambassador Hwang Joon-kook made the remarks, citing Seoul's casualty assessment that of some 12,000 North Korean troops dispatched to Russia, more than 300 were killed with around 2,700 injured.

"The testimonies of two North Korean soldiers, recently captured by Ukraine's military in the Kursk region, clearly demonstrate that the North Korean troops are engaged in combat and being dissipated as expendables," the ambassador said, noting Pyongyang still refuses to acknowledge its troop deployment.

Hwang also said that as a native speaker of Korean himself, he can "definitely" tell that the two captured soldiers spoke in Korean with North Korean accents.

He ascribed the large number of North Korean casualties to what he called "inhumane" tactics on the front lines.

"The North Korean soldiers used old-fashioned human wave tactics and were then chased and attacked by Ukrainian drones," he said.

"According to the reports, they even were crossing land mine fields in a single column, 3 to 4 meters apart, like human mine detectors without cover or mine-clearing vehicles," he said.

Hwang went on to cite South Korea's intelligence reports that news of the North's troop deployment is now spreading across North Korea, with families of the dispatched troops having expressed "utmost fear and anxiety of their sons and brothers being used as slave soldiers and mere cannon fodder."

"Given all this information, we plainly see that the DPRK only treats its troops as a cynical means of sustaining its regime, as well as advancing its illegal WMD program financially and technologically," he said.

DPRK is short for the North's official name, the Democratic People's Republic of Korea, while WMD stands for weapons of mass destruction.

Hwang renewed Seoul's condemnation of the troop dispatch and the ongoing military cooperation between Moscow and Pyongyang.

"This must stop immediately," he said. (Yonhap)