SEOUL, September 6, 2018 (News Wires) - North Korea's Kim Jong Un has given his first time line to achieve denuclearisation, aiming for the end of US President Donald Trump's first term, and has agreed to a third summit with his South Korean counterpart, Seoul officials said on Thursday. Kim and South Korean President Moon Jae-in will meet in Pyongyang on September 18-20 and discuss "practical measures" towards denuclearisation, Moon's national security adviser, Chung Eui-yong, said a day after meeting Kim. The summit could provide renewed momentum to talks over denuclearisation between North Korea and the United States, after Trump canceled a visit to Pyongyang by his secretary of state last month citing lack of progress. Kim told South Korean officials his faith in Trump was "unchanged" and that he wanted denuclearisation and an end to hostile relations with the United States before Trump's first term in office ends in early 2021, Chung said. "He particularly emphasised that he has never said anything negative about President Trump," Chung said. The remarks represent Kim's first timeline for dismantling North Korea's nuclear weapons programme. In previous, failed talks, North Korea has said it could consider giving up its nuclear programme if the United States provided security guarantees by removing troops from South Korea and withdrawing its so-called nuclear umbrella of deterrence from the South and Japan. US officials involved in the latest negotiations have said North Korea has refused to even start discussions about defining "denuclearisation" or other key terms such as "verifiable" and "irreversible", and has insisted the United States must first agree to simultaneous steps to reduce economic pressure. Chung said Kim had stressed the need for the United States to reciprocate North Korea's initial moves, which have included dismantling a nuclear test site and a missile engine facility. The US embassy in Seoul said it had no information to share on the matter.