Seoul, South Korea - South Korea - South Korean spy agency told lawmakers on Wednesday that an estimated 4,700 North Korean soldiers were killed or injured while fighting Russian and Ukrainian forces.

The assessment comes two days after North Korea first dispatched combat troops to help Russia retake parts of the Kursk region, which lost a portion of the Kursk region last year.

According to one of the lawmakers attending the meeting, the South Korean National Intelligence Agency said in a closed-door parliamentary committee briefing that the North Korean National Intelligence Agency said North Korea suffered 4,700 casualties, including 600 deaths, including 600 deaths in the Russian-Ukrainian battlefield.

Lee told reporters that between January and March, 2,000 injured North Korean soldiers were repatriated to North Korea by air or train. He quoted New York State as saying that the dead North Korean soldiers were cremated in Russia and their bodies were sent home.

The NIS said in January that about 300 North Korean soldiers died and another 2,700 were injured, and the South Korean military increased its estimated casualties to 4,000 last month.

On Monday, North Korea announced that its leader Kim Jong-un decided to send troops to "annihilate and eliminate the neo-Nazi occupiers of Ukraine and cooperate with the Russian armed forces to liberate the Kursk region." Russian President Vladimir Putin then issued a statement thanking North Korea and promising not to forget the sacrifice of North Korean soldiers.

Both Kim and Putin said North Korea's deployment was conducted under its country's 2024 defense treaty and asked for assistance if the other party was attacked. The United States, South Korea and its partners say North Korea has been providing a large number of conventional weapons to supplement Russia's dry-up stock. They suspect Russia is providing North Korea with military and economic aid in return.

U.S., South Korea and Ukrainian officials said that last fall, North Korea sent 10,000-12,000 soldiers to Russia. South Korean military said in March that earlier this year, North Korea sent about 3,000 troops to Russia.

In a briefing on Wednesday, NIS said Russia provided North Korean air defense missiles, electronic warfare equipment, drones and technology for spy satellite launches.

King quoted New York City as saying that under the bilateral industrial cooperation plan, 15,000 North Korean workers have also been sent to Russia. The lawmaker said North Korea's missiles and artillery numbers are worth billions of dollars, but New York City has not yet seen any signs that Russia has sent cash to Russia.