North Korea threatened to end the “hard-won atmosphere of stability on the Korean Peninsula” on Thursday, in response to Secretary of State Mike Pompeo’s efforts to enforce economic sanctions against the regime.

“[T]here is no guarantee that the hard-won atmosphere of stability on the Korean Peninsula will continue,” the North Korean foreign ministry warned in a message carried by state-run KCNA.

[Opinion: North Korea's new anger is a sign Trump's strategy working]

Pompeo and other U.S. officials don’t want any international sanctions eased until North Korean dictator Kim Jong Un takes substantial steps to roll back his nuclear weapons and ballistic missile program. Kim’s diplomats have taken offense at this position, which the Trump administration believes is necessary to prevent North Korea from backsliding as the regime has in previous talks, and lashed out with a renewal of insulting rhetoric.

“[S]ome high-level officials within the U.S. administration are making baseless allegations against us and making desperate attempts at intensifying the international sanctions and pressure,” the foreign ministry said Thursday. “The international society is struck by this shameless and impertinent behavior of the U.S., and we also closely follow the U.S. behavior with high vigilance against their intentions.”

Pompeo is leading the Trump administration’s negotiations, while urging world powers and North Korean neighbors to continue enforcing economic sanctions imposed by the United Nations Security Council.

“In light of how many flimsy agreements the United States has made in previous years, this president will ensure that no potential agreement will fail to adequately address the North Korean threat,” Pompeo said, days before Trump’s historic summit with Kim. “Sanctions will remain until North Korea completely and verifiably eliminates its weapons of mass destruction programs. If diplomacy does not move in the right direction — and we are hopeful that it will continue to do so — those measures will increase.”

Pompeo reportedly has proposed that North Korea hand over a substantial proportion of its nuclear weapons stockpile, only to be rebuffed. The Kim regime’s top diplomat is demanding sanctions relief in response to more limited gestures, such as the return of American war dead from the Korean c onflict and the cessation of missile testing.

[Related: John Bolton: North Korea failing to live up to commitment to denuclearize]

“It is essential for both sides to take simultaneous actions and phased steps to do what is possible one after another,” North Korean Foreign Minister Ri Yong Ho said Saturday.

Pompeo’s team isn’t backing down. “We encourage all countries to maintain sanctions, and to not skirt sanctions, and to make sure sanctions are adhered to,” State Department spokeswoman Heather Nauert told reporters during a Thursday press briefing.

China and Russia have undermined those calls, according to U.S. officials, most notably by selling vast quantities of oil to the regime despite a strict cap on oil exports to the country that was imposed by the U .N . Security Council in December.

“As long as the U.S. denies even the basic decorum for its dialogue partner and clings to the outdated acting script which the previous administrations have all tried and failed, one cannot expect any progress in the implementation of the DPRK-U.S. joint statement including the denuclearization,” the North Korean foreign ministry said Thursday.