WASHINGTON -- Declaring a formal end to the Korean War would "obviously" be part of efforts to denuclearize the Korean Peninsula, US Secretary of State Mike Pompeo said Wednesday, calling for North Korea's return to denuclearization talks.

Pompeo's remarks come after South Korean President Moon Jae-in urged international support for declaring the war's end in his speech before the United Nations General Assembly last month.

"So our position on that set of issues, that suite of issues with respect to the denuclearization of North Korea -- a brighter future for the North Korean people, which would obviously include documents that would change the status between North and South Korea -- there's been no change in the way the United States thinks about this," Pompeo told a press briefing, referring to the declaration of the war's end as documents.

South and North Korea technically remain at war as the 1950-53 war ended with an armistice, not a peace treaty.

Moon had said the end-of-war declaration will open the door to "complete denuclearization and permanent peace regime on the Korean Peninsula."

His call, however, prompted concerns that Seoul may be trying to declare the war's end even before the North gives up its nuclear ambitions, which many believe would be a huge incentive to the communist state for nothing in return.

Such concerns were further propelled by the fact that North Korea continues to stay away from denuclearization negotiations.

Moon's national security adviser, Suh Hoon, has clarified that Seoul only seeks to declare the war's end as part of North Korea's denuclearization process.

"It is common sense that the declaration of the war's end cannot be dealt with separately (from denuclearization)," he said after meeting with the top US diplomat here in Washington Thursday, adding the only remaining issue was when such a declaration could be made.

Pompeo urged North Korea to return to the negotiating table.

"We continue to believe that there is an important, good outcome for global peace and stability and for the North Korean people and we hope we can get back to the (dialogue) table and begin to have those discussions in a serious way that would ultimately lead to what the president of South Korea was speaking to," he said at the press briefing.

Pyongyang has stayed away from any denuclearization negotiations since leader Kim Jong-un's second and last bilateral summit with US President Donald Trump, held in Hanoi in February 2019, ended without a deal.

The first Trump-Kim summit was in Singapore in June 2018. (Yonhap)