U.S. Secretary of State Mike Pompeo speaks at a news conference at Lazienki Palace in Warsaw, Feb. 12. Reuters

U.S. Secretary of State Mike Pompeo said Thursday that he expects President Donald Trump to discuss the possibility of formally ending the 1950-53 Korean War at his next summit with North Korean leader Kim Jong-un.

Trump and Kim are scheduled to meet in Hanoi, Vietnam, Feb. 27-28 to discuss the dismantling of North Korea's nuclear weapons program in exchange for U.S. security guarantees.

An end-of-war declaration is a key concession North Korea has demanded in return for the denuclearization it committed to at the first Trump-Kim summit in Singapore in June.

"It's something we've had a lot of talks about," the top U.S. diplomat said in an interview with Fox News held 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."

The peace declaration under discussion is likely a political statement that is different from a peace treaty. A treaty would be legally binding and involve all the signatories to the armistice that ended the three-year conflict.