Russia's report said that the number of North Korean workers with valid work permits has fallen from 30,023 to 11,490 people.
In its report, China, the strongest ally in North Korea, said more than half of its earnings revenue North Korean citizens had been repatriated.
A UN diplomat confirmed to CNN that one-page reports from Beijing and Moscow were sent to the Sanctions Committee, as required by a resolution of December 2017, which required repatriation of all North Korean workers by the end of this year.
China's report also noted that it does not want the submission to be made public.
The United States has pushed over recent years for sanctions against North Korea to be strengthened.
The United States believes that North Korea has about 100,000 workers abroad, with the majority in China and Russia. North Korean workers abroad are considered a source of funding for the country's nuclear and missile program, so repatriation of them cuts a vital lifeblood of the regime.
North Korea has long sought the elimination of UN sanctions that have played a perverse role in their finances and portrayed them as a violation. summit in March.