In a statement to the U.N. Security Council on Wednesday, Ukraine's delegation said the three generals are among at least 500 North Korean officers sent to Russia.

Plans call for the North Korean troops to be formed into at least five formations of 2,000-3,000 soldiers each, and integrated into Russian units to conceal their presence, the statement said.

Russia has not denied the involvement of North Korean troops in the war, which it has been waging in Ukraine since February 2022.

After an initial denial, North Korea has also since defended the idea of deploying troops as in line with international law.

At the same Security Council meeting, Russian envoy Vassily Nebenzia said Russia's military interaction with North Korea does not violate international law and that Moscow has the right to seek aid from its partners.

Ukraine identified Colonel General Kim Yong Bok, a senior general with command of special forces troops, including the XI Corps, also known as the Storm Corps, which the South Korean intelligence service said has been dispatched to Russia.

Michael Madden, a North Korea leadership expert with the U.S.-based Stimson Center said Kim's role appears to be larger, running the KPA Light Infantry Training Guidance Bureau which includes the XI Corps and light infantry units deployed to KPA corps units and seconded to special missions for the Reconnaissance General Bureau, which is North Korea's main spy agency.

Kim has appeared at seven events with North Korean leader Kim Jong Un this year, including special forces exercises.

"This is a large and almost unprecedented deployment for the KPA," said Madden, who believes the general is in Russia as a representative of Kim Jong Un.

"As such, there are a number of administrative and liaison tasks so Kim Jong Un has sent in Kim Yong Bok as a proxy decision-maker until the KPA unit presence is fully stood up."

Kim Yong Bok may eventually defer command to a subordinate KPA officer of a Senior Colonel or Major General rank, Madden added.

Other top officers identified by Ukraine include Colonel General Ri Chang Ho, Deputy Chief of the General Staff, head of the Reconnaissance General Bureau and Major General Sin Kum Cheol, Head of the Main Operational Directorate.

As head of North Korea's main intelligence service since about 2022, Ri has been sanctioned by South Korea, which alleged he oversaw major cyber hacking efforts to steal technology and foreign currency.

Like Kim Yong Bok, Ri also accompanied leader Kim Jong Un to an unusually large number of events this year, including inspecting an east coast navy base

Madden said Sin's career is unclear, but given his one-star rank, is likely to assume command of the North Korean troops in Russia once Kim Yong Bok and Ri Chang Ho depart.