U.S. Secretary of State Mike Pompeo has said Washington and Pyongyang might discuss ending the Korean war in an upcoming summit meeting in Vietnam.

U.S. President Donald Trump and North Korean leader Kim Jong-un are set to meet for their second summit in the Vietnamese capital Hanoi later this month to discuss denuclearization and the lifting of sanctions on Pyongyang.

"It's something we've had a lot of talks about," said Pompeo in an interview with Fox News in Warsaw, Poland.

"In fact, my team will redeploy to Asia here in a day or two to continue conversations around all elements that were discussed back in Singapore. Remember we not only discussed denuclearization, but we talked about creating security mechanisms, peace mechanisms on the Korean Peninsula. I hope the two leaders have a chance to talk about that as well. I fully expect that they will," he said.

Pompeo refused to give any timetable on the denuclearization of the Korean Peninsula.

"One of the core principles of the Trump doctrine is we don’t tell our adversaries what we’re going to do. And so we’ve had lots of conversations about how we hope this proceeds, but I just don’t have anything I can say about a deadline like you’re supposing," he said.

Pompeo is hosting a peace and security conference on the Middle East in the Polish capital along with U.S. allies.