North Korean leader Kim Jong Un said he would halt nuclear tests and intercontinental missile launches, and instead pursue economic growth and peace in a Saturday announcement welcomed by US President Donald Trump ahead of a much-anticipated summit between the two men. Pyongyangs declaration comes less than a week before the North Korean leader meets South Korean President Moon Jae-in for a summit in the Demilitarized Zone that divides the peninsula, ahead of the eagerly-awaited encounter with Trump himself in late May or early June. But Kim gave no indication Pyongyang might be willing to give up its nuclear weapons, or the missiles with which it can reach the mainland United States. The North had successfully developed its arsenal, including miniaturizing warheads to fit them on to missiles, Kim said, and so "no nuclear test and intermediate-range and inter-continental ballistic rocket test-fire are necessary for the DPRK now". As such the Norths nuclear testing site was no longer needed, he told the central committee of the ruling Workers Party, according to the official KCNA news agency. The party decided that nuclear blasts and ICBM launches will cease as of Saturday -- the North has not carried any out since November -- and the atomic test site at Punggye-ri will be dismantled to "transparently guarantee" the end of testing. Within minutes of the report being issued, Trump tweeted: "This is very good news for North Korea and the World - big progress! Look forward to our Summit." Seoul welcomed the announcement, calling it "meaningful progress" towards the denuclearization of the Korean peninsula. China also said it "believes the decision to stop nuclear tests and focus on developing the economy and improving peoples living standards will help further ease the situation on the Korean peninsula and help promote the process of denuclearisation and attempts to find a political settlement." But Kim offered no sign he might be willing to give up what he called the Norths "treasured sword", saying its possession of nuclear weapons was "the firm guarantee by which our descendants can enjoy the most dignified and happiest life in the world". Japan -- which has seen missiles fly over its territory -- gave a mixed response, with Prime Minister Shinzo Abe offering a cautious welcome but his defense minister saying North Korea did not mention the short- or medium-range missiles that put Tokyo within reach. The US is seeking the complete, verifiable and irreversible denuclearization of the North, while according to Moon, Pyongyang wants security guarantees, potentially leaving much space for disagreement.