North Korea's leader has pledged to immediately suspend nuclear and missile tests and shut down a nuclear test site as he prepares for meetings with the South Korean and US presidents.
Kim Jong-un said the nuclear test site in the northern area of the country had completed its mission and would be dismantled, the state Korean Central News Agency reported on Saturday.
“I solemnly declare that we have accomplished credible weaponisation of nuclear forces,” Mr Kim was quoted as saying at a ruling party meeting.
“Our decision to suspend nuclear tests is part of the world’s important steps for nuclear disarmament and our republic will join global efforts to completely suspend nuclear tests.”
US president Donald Trump hailed the announcement as "very good news" for the world.
Mr Kim' announcement comes ahead of his talks this week with South Korean President Moon Jae-in and a summit with Mr Trump planned for May or June. While the North Korean leader reiterated that his regime had accumulated enough of a nuclear deterrent, the announcement of a plan to dismantle the test site suggests he is seeking to further ease tensions ahead of those meetings.
South Korea said the decision signified "meaningful" progress toward denuclearisation of the peninsula and would create favourable conditions for the meetings with Mr Moon and Mr Trump.
The two Koreas on Friday set up and tested a direct phone line for their leaders, and the first call between Mr Moon and Mr Kim is expected take place sometime before their April 27 meeting.
China, the North's only major ally, said Mr Kim's decision would help "ameliorate the situation on the peninsula", while Russia called on the South and the US to reduce their military activity in response.
Japanese Prime Minister Shinzo Abe said Mr Kim's promise must lead to action.
"What's important is that this leads to complete, verifiable denuclearisation. I want to emphasise this," he said.
The European Union's foreign affairs chief Federica Mogherini called for an "irreversible denuclearisation" of the country, while the German Foreign Minister Heiko Maas said the North must "disclose its complete nuclear and missile programme in a verifiable way".
North Korea had already effectively halted weapons tests for the past five months, after firing a missile on November 29 believed to be capable of reaching any city in the US. After that launch, which prompted the most restrictive UN sanctions yet, Mr Kim declared his regime’s decades-long quest for nuclear weapons “complete”.
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The North Korean leader then began making overtures for a rapprochement with Seoul, beginning with participation in the Winter Olympics hosted by the South in February.
But Mr Moon warned on Thursday that implementing any deal with North Korea would be challenging.
“Realistically speaking, we’re just entering the threshold for a dialogue,” he said. “It’s too early to be confident of the success of the talk.”
Vipin Narang, an expert on nuclear policy at MIT, told the Financial Times that closing a testing site would not preclude North Korea conducting atmospheric nuclear tests and that missile tests could still be conducted under the guise of space vehicle launches.
“The big points aren’t new. They said in November they didn’t need to test any more after the HS-15 test and the purported thermonuclear test,” Mr Narang said.
“And the testing moratorium was pledged to [South Korea] in March so long as dialogue was progressing. So this just formalises that. It’s not much progress, in my opinion. Though many want to believe it is.”
Joel Wit, a senior fellow at the US-Korea Institute at the Johns Hopkins School of Advanced International Studies called the announcement a “very serious initiative", however.
"It fits right in with North Korean policy and what they’ve been saying for a while,” Mr Wit, who was involved in North Korea talks from 1993 to 1995, told Bloomberg. “They’ve decided that this is the moment to shift gears and to focus on developing their economy, end of story.”
The decision was made at a plenary meeting of the central committee of the ruling Worker's Party of Korea Friday, the KCNA said.
Mr Trump revealed on Wednesday that CIA director Mike Pompeo had recently travelled to North Korea and struck up a "good relationship" with Mr Kim at a secret meeting. The highest-level contact between the two countries for 20 years, came as the two countries prepare for a historic meeting between Mr Kim and Mr Trump.
Details of the preparatory trip first emerged in The Washington Post, which said the meeting took place just over two weeks ago and shortly after Mr Pompeo was nominated to become the US secretary of state.
Mr Trump confirmed the meeting in a tweet.
"Mike Pompeo met with Kim Jong-un in North Korea last week," he wrote. "Meeting went very smoothly and a good relationship was formed."