Seoul, Feb 25 (IANS): The US and North Korea might agree on how to declare an end to the Korean War at the upcoming meeting of their leaders this week in Vietnam, an official from Seoul's presidential office said on Monday.

"I believe the possibility is open. There is no way of knowing what kind of a declaration it might be, but I believe the US and North Korea may reach an agreement on the declaration of war's end at any degree," presidential office spokesman, Kim Eui-kyeom said.

US President Donald Trump and North Korean leader Kim Jong-un are set to hold their second meeting in Hanoi on Wednesday and Thursday. The two first met in Singapore in June 2018, reported Yonhap news agency.

The 1950-53 Korean War ended only with an armistice.

Seoul earlier insisted that declaring a formal end to the war should at least involve the divided Koreas and the US.

Kim Eui-kyeom claimed the two Koreas may have already made a de facto declaration of the war's end when their militaries signed an agreement to forgo all hostile acts shortly after South Korean President Moon Jae-in visited Pyongyang for his third and latest summit with the North Korean leader in September.

He insisted that Seoul and Beijing may have already done so when they established their diplomatic ties, adding that the US and China normalised their bilateral relations in 1979.

China fought on the North's side in the Korean War.

"Therefore, the only countries left are the North and the US," he said. "Should the North and the US declare the war's end, it (the war's end) would be achieved in the practical sense."

The spokesman said replacing the Korean armistice with a peace treaty would take some time and that it must be a multilateral effort involving both Koreas and China.