North Korea on Thursday decried the United States over efforts to build a new mechanism for the monitoring of sanctions enforcement against the North and warned of "powerful practical actions" to build up its military strength.

The US has pledged to work with South Korea and other countries to establish an alternative with the mandate of a UN expert panel monitoring sanctions enforcement that's set to expire at the end of April following Russia's veto to extend it last month.

"Clearly speaking, if the US introduces a new version of sanctions against the DPRK, the latter will take a new opportunity necessary for its upward readjustment of force which the US is most afraid of," Kim Un-chol, vice minister for US affairs at the North's foreign ministry, said in a statement carried by the Korean Central News Agency.

DPRK stands for the North's official name, the Democratic People's Republic of Korea.

The official said new sanctions will only result in Pyongyang further building up its military power.

"Whenever the US cooked up a new sanctions resolution in the UN arena, it triggered a more powerful and more developed nuclear test of the DPRK," Kim said, vowing to take "more powerful practical actions" to beef up its military technical strength.

During a visit to the Demilitarized Zone (DMZ) separating the two Koreas earlier this month, US Ambassador to the UN Linda Thomas-Greenfield said Washington is looking at "out of the box" options, suggesting that "all possibilities" are on the table, even outside of the UN regime.

The latest statement marked the first such statement issued by a vice minister in charge of US affairs at Pyongyang's foreign ministry since December 2019. Similar statements have mostly been issued by lower-ranking officials handling US affairs. (Yonhap)