The U.S. will not lift sanctions on North Korea until the country makes substantial progress toward denuclearization, Secretary of State Mike Pompeo said Monday, but Washington nevertheless still has “hope” that the two sides can come together and strike a deal.

The comments, first reported by South Korea’s Yonhap News Agency, came after the DPRK accused Pompeo of undermining U.S. President Donald Trump’s unprecedented diplomatic efforts with the North.

That accusation came after Pompeo implored the G7 foreign ministers last week to “remain united” in stopping Pyongyang’s development of nuclear