President Moon Jae-in and U.S. President Donald Trump discussed signing of a peace treaty ending the Korean War, Cheong Wa Dae spokesman Yoon Young-chan said.

The two met in Washington to discuss the upcoming summit between Trump and North Korean leader Kim Jong-un.

The two Koreas vowed during their summit last month to declare an end to the Korean War this year and pursue trilateral or four-way talks that could include China, which fought alongside North Korea in the war.

China has insisted that it must be included in the process, but the U.S. is against. "The U.S. and China are expected to engage in a tug of war over this issue," a diplomatic source said.

Asked about China's participation in the process, a high-ranking Cheong Wa Dae official said, "Opinions have been exchanged, but no conclusion has been reached."

The legal situation is complicated since North Korea was officially at war with the UN, which is still nominally in charge of armistice protocol, even though the UN forces commander happens to be the chief of the U.S. Forces Korea.

It was China's intervention that cemented the division of the Korean Peninsula, scuppering U.S. hopes to conquer the entire territory.

