North Korea's ambassador to the United Nations said efforts to set up a new panel to monitor sanctions against his country would end in failure, state media reported on Sunday.

Kim Song's comments come after Russia's veto in March which effectively ended official UN monitoring of sanctions imposed on the isolated country for its pursuit of banned nuclear and weapons programs.

Seoul and Washington say North Korean leader Kim Jong Un has been shipping weapons to Russia, possibly in exchange for Moscow's technical assistance for Pyongyang's budding spy satellite programs.

Last year, North Korea conducted a record number of missile tests -- in defiance of UN sanctions in place since 2006 and despite warnings from Washington and Seoul -- having declared itself as an "irreversible" nuclear weapons state in 2022.

"The hostile forces may set up the second and third expert panels in the future, but they are all bound to meet self-destruction with the passage of time," envoy Kim Song said in an English statement carried by the official KCNA news agency on Sunday.

The dissolution of the UN panel after Moscow's veto, he said, was a "judgement made by history on an illegal, plot-breeding organization... to stamp out a sovereign state's right to existence".

The envoy expressed gratitude towards Moscow last month, stating that Pyongyang "highly appreciates the Russian Federation's veto" that blocked the renewal of the expert sanctions panel, "as an independent exercise of the right to international justice and impartiality".

But during a visit to Seoul in April, US ambassador to the UN Linda Thomas-Greenfield stressed the importance of ensuring enforcement of the sanctions on North Korea.

She said Washington was collaborating with Seoul, Tokyo, and others to explore "some creative ways" and "out-of-the-box thinking" to ensure the continuation of monitoring activities.

"The point here is that we cannot allow the work that the panel of experts were doing to lapse."