North Korea's ambassador to the United Nations on Thursday thanked Russia for using its veto power to effectively end official UN monitoring of sanctions on his nation.

Kim Song said Pyongyang "highly appreciates the Russian Federation's veto" that blocked the renewal of an expert sanctions panel, "as an independent exercise of the right to international justice and impartiality."

North Korea has been under mounting sanctions since 2006, put in place by the UN Security Council in response to its nuclear program.

But since 2019, Russia and China have tried to persuade the Security Council to ease the sanctions, which have no expiration date.

Two weeks ago, Russia vetoed a vote extending the mandate of the committee responsible for sanctions monitoring, while China abstained.

The move prompted backlash from Western capitals, as it came amid a probe into alleged arms transfers between Moscow and Pyongyang.

Seoul has accused Pyongyang of sending thousands of containers of weapons to Moscow for use in Ukraine.

During a debate Thursday at the General Assembly, which must follow any veto, Kim attacked what he called "the heinous hostile policy of the US to trample underfoot (North Korea's) sovereignty (and) right to development and existence."