Upcoming talks between North Korea and South Korea should seek to formally end the decades-old Korean War with a peace treaty, a South Korean official said – an outcome Donald Trump endorsed as his administration prepares for an unprecedented summit with North Korean leader Kim Jong-un.

The conflict that fractured the Korean Peninsula in the 1950s ended in a truce rather than the signing of a peace treaty. A recent thaw in relations between the two countries is fuelling hopes of an enduring detente – and a more definitive end to the war than a 1953 armistice has provided.

“A peace treaty should be signed in the inter-Korean summit so that we can build peace and ensure peaceful coexistence”, South Korean cultural minister Do Jong-When told reporters, according to the Financial Times

In remarks to reporters, Mr Trump said South Korea “has plans to meet with North Korea to see if they can end the war” and threw his weight behind the effort.

“Subject to a deal, they would certainly have my blessing and they do have my blessing to discuss that”, Mr Trump said.

The planned inter-Korean summit builds on a sustained diplomatic overture from Pyongyang that reversed tense months of weapons tests and belligerent rhetoric.

After North Korea carved out a space for dialogue by dispatching athletes to South Korea for the Winter Olympics – along with Mr Kim’s sister – and then followed up with additional meetings between North Korean and South Korean leaders, Mr Kim conveyed to Mr Trump an extraordinary invitation to meet.

The American president has accepted the face-to-face encounter, which Mr Kim floated as part of an effort to “denuclearise” the Korean peninsula, according to a South Korean official. Mr Kim also pledge to halt new weapons tests.

Mr Trump told reporters the US was engaging in “direct talks at very high levels” with Pyongyang, saying “North Korea is coming along” and predicting a summit by June. But he left open the possibility the effort collapses, in keeping with his administration both hailing the opportunity for a diplomatic breakthrough and continuing to project wariness about Mr Kim’s motives.

“We’ll be having discussions with Kim Jong Un very soon”, Mr Trump said. “That will be taking place probably in early June or before that assuming things go well. It’s possible things won’t go well and we won’t have the meetings and we’ll just continue to go on this very strong path we have taken.”

National Security Council official Matthew Pottinger reiterated to reporters that Mr Trump’s aim for talks with Mr Kim was “the permanent denuclearisation of North Korea” but did not comment specifically on South Korea potentially seeking a peace treaty. 

“I would just say that the US and South Korea are as much aligned and coordinated on their summit as we are on a US summit”, he said.

Leaders in Seoul and Pyongyang have embraced the possibility of warmer relations. Recently elevated South Korean president Moon Jae-in rose to office in part by vowing to repair ties with North Korea.

And Pyongyang has issued calls for unity, sending a rare announcement to all Koreans earlier this year exhorting them to “smash” obstacles to reunification and to “promote contact, travel, cooperation between North and South Korea”.