Kim Jong-un has said he still has “faith” in stalled peace talks with Donald Trump, as North and South Korea announced a historic new summit will take place between the two nations in less than a fortnight.

Moon Jae-in will become the first South Korean president to visit Pyongyang in more than 10 years when he travels to the North Korean capital for talks with Mr Kim on 18 September. The two-day trip will be the pair’s third meeting since April.

The summit between the two Koreas will be a crucial indicator of whether nuclear negotiations with the US will proceed. South Korea’s Mr Moon has played a big role in keeping those talks alive.

Seoul said it had forwarded a message from Mr Trump to Mr Kim, which North Korea reciprocated.

In comments that were conveyed on Thursday by both North Korean media and South Korean mediators, Mr Kim reportedly reaffirmed his commitment to a nuclear-free Korean Peninsula and the suspension of all future long-range missile tests.

“Chairman Kim Jong-un has made it clear several times that he is firmly committed to denuclearise, and he expressed frustration over scepticism in the international community over his commitment,” Chung Eui-yong, Mr Moon’s national security adviser and the head of the South Korean delegation to Pyongyang, told reporters in Seoul.

“He said he’s pre-emptively taken steps necessary for denuclearisation and wants to see these goodwill measures being met with goodwill measures.”

The North Korean leader told the South’s officials that his faith in Mr Trump remains “unchanged” since their historic meeting in Singapore in June, expressing his wish to denuclearise and form friendly relations with the US before the end of Mr Trump’s first term of office, Chung said.

Chung added that in the meantime, Mr Kim and Mr Moon would discuss “practical measures” toward denuclearisation during the summit later this month.

Mr Moon is seen as eager to keep the diplomacy alive in part so that he can advance his ambitious engagement plans with the North, which would need US backing to succeed.

The inter-Korean summit comes on the eve of a gathering of world leaders at the United Nations in New York at the end of September, but Seoul said on Thursday that it was unlikely Mr Kim would attend.

Seoul has indicated an interest in Mr Kim and Mr Trump meeting in New York, and Mr Trump, who is facing growing domestic turmoil, has hinted that another summit could happen.

While pushing ahead with summits and inter-Korean engagement, Seoul is trying to persuade Washington and Pyongyang to proceed with peace and denuclearisation processes at the same time so they can overcome a growing dispute over the sequencing of the diplomacy.

Seoul and Pyongyang both want a declaration to formally end the 1950-53 Korean War.

US officials have insisted that a peace declaration, which many see as a precursor to the North eventually calling for the removal of all US troops from the Korean Peninsula, cannot come before North Korea takes more concrete action toward abandoning its nuclear weapons.

Such steps may include providing an account of the components of its nuclear programme, allowing outside inspections and giving up a certain number of its nuclear weapons during the early stages of the negotiations.

The Korean War ended with an armistice, leaving the peninsula technically still at war.

Mr Moon has made an end-of-war declaration an important premise of his peace agenda with North Korea.