PYONGYANG, North Korea — After months of threatening to wage a nuclear war, North Korea did an about-face Sunday and issued a surprise proposal to the United States, its No. 1 enemy: Let’s talk.

But the invitation from North Korea’s National Defense Commission, the powerful governing body led by leader Kim Jong Un, comes with caveats: No preconditions and no demands that Pyongyang give up its prized nuclear assets unless Washington is willing to do the same — ground rules that make it hard for the Americans to accept.

Washington responded by saying that it is open to talks — but only if North Korea shows it will comply with U.N. Security Council resolutions and live up to its international obligations.

“As we have made clear, our desire is to have credible negotiations with the North Koreans, but those talks must involve North Korea living up to its obligations to the world, including compliance with U.N. Security Council resolutions, and ultimately result in denuclearization,” U.S. National Security Council spokeswoman Caitlin Hayden said in a statement. “We will judge North Korea by its actions, and not its words and look forward to seeing steps that show North Korea is ready to abide by its commitments and obligations.”

North Korea’s call for “senior-level” talks between the Korean War foes signals a shift in policy in Pyongyang after months of acrimony.

Pyongyang ramped up the anti-American rhetoric early this year after its launch of a long-range rocket in December and a nuclear test in February drew tightened U.N. and U.S. sanctions. Posters went up across the North Korean capital calling on citizens to “wipe away the American imperialist aggressors,” slogans that hadn’t been seen on city streets in years.

The U.S. and ally South Korea countered the provocations and threats by stepping up annual springtime military exercises, which prompted North Korea to warn of a “nuclear war” on the Korean Peninsula.

But as tensions began subsiding in May and June, Pyongyang began making tentative, if unsuccessful, overtures to re-establish dialogue with Seoul and Washington.

Earlier this month, it proposed high-level talks with South Korea — the first in six years. But plans for two days of meetings last week in Seoul dramatically fell apart even before they began amid bickering over who would lead the two delegations.

Meanwhile, the virulent anti-American billboards plastered across the city were taken down. And on Sunday, as scores of people fanned out across Pyongyang to help carry out the latest urban renewal projects in the capital — landscaping and construction — the National Defense Commission issued a statement through state media proposing talks with the U.S. to ease tensions and discuss a peace treaty formally ending the Korean War.

North Korea fought against U.S.-led United Nations and South Korean troops during the three-year Korean War in the early 1950s, and Pyongyang does not have diplomatic relations with either government. The Korean Peninsula remains divided by a heavily fortified border.

Reunifying the peninsula was a major goal of North Korea’s two late leaders, Kim Il Sung and Kim Jong Il, and is a legacy inherited by current leader Kim Jong Un. North Korea is expected to draw attention to Korea’s division in the weeks leading up to the 60th anniversary in July marking the close of the Korean conflict, which ended in an armistice.