President Donald Trump says the North Korean nuclear crisis is a long way from being resolved, striking a cautious note a day after the Pyongyang’s pledge to end its nuclear tests raised hopes ahead of talks with with South Korea and the United States.

“We are a long way from conclusion on North Korea, maybe things will work out, and maybe they won’t – only time will tell,” Mr Trump said on Twitter on Sunday.

North Korea said on Saturday it was suspending nuclear and missile tests and scrapping its nuclear test site, and instead pursuing economic growth and peace.

World leaders welcomed the announcement, but some expressed doubts about Mr Kim’s intentions and South Korean President Moon Jae-in will be under intense international scrutiny when he meets him on Friday at the first North Korea-South Korea summit in more than a decade.

In a tweet minutes before he tempered enthusiasm about the North’s statement, Mr Trump interpreted it as a pledge to denuclearise: “Wow, we haven’t given up anything & they have agreed to denuclearisation (so great for World), site closure, & no more testing!”

Sleepy Eyes Chuck Todd of Fake News NBC just stated that we have given up so much in our negotiations with North Korea, and they have given up nothing. Wow, we haven’t given up anything & they have agreed to denuclearization (so great for World), site closure, & no more testing!

— Donald J. Trump (@realDonaldTrump) April 22, 2018

However, Mr Kim’s announcement did not include a commitment to scrap existing nuclear weapons and missiles, and there are doubts he would ever give up the nuclear arsenal his country has been developing for decades.

Mr Kim said North Korea no longer needed to test nuclear bombs or intercontinental ballistic missiles now that his country had the weapons, and he would gear all efforts towards economic development.

With past failures in mind, some expressed concern about the North’s intentions.

“North Korea has a long history of raising the issue of denuclearisation and has committed to freeze its nuclear weapons programs in the past. We all remember how those pledges and commitments went down over past decades,” professor of North Korean Studies at Korea University in Seoul Nam Sung-wook said.

“Although the North’s announcement is quite dramatic, it’s natural for the world to be extra sensitive to every word spoken by Kim.”

In Washington, Bob Corker, the Republican chairman of the Senate Foreign Relations Committee, said the US government viewed Mr Kim’s pledge with scepticism.

“This is a great public relations effort by Kim Jong Un,” Mr Corker said on CNN. “I think everyone within the administration and congress approaches this with scepticism and caution.”

Mr Kim is expected to meet Mr Trump in late May or early June, the first meeting between sitting leaders of the two countries.

US officials say North Korea had in the past repeatedly reneged on denuclearisation agreements, the latest in 2012 when the North launched a long-range rocket after agreeing to a moratorium on missile testing.

White House legislative affairs director Marc Short said on NBC’s Meet the Press the US goal remains “full denuclearisation” in which Pyongyang no longer has nuclear weapons.

South Korea said the North’s testing pledge signified “meaningful” progress that would create good conditions for successful summits with Seoul and Washington.

-Reuters