South Korean President Moon Jae-in on Wednesday urged world governments to encourage North Korea to advance toward denuclearisation by "responding positively" to leader Kim Jong Un's "new choices".Addressing the UN General Assembly, Moon praised his North Korean counterpart - with whom he has held three summits - saying he had "changed the direction of the political situation" on the Korean peninsula."North Korea moved out of longstanding isolation on its own initiative and stands before the international community once again," Moon said."Now it is the international community's turn to respond positively to North Korea's new choices and efforts."Moon, who has embraced dialogue with the North, advocates a step-by-step approach that would push Pyongyang to scrap its nuclear and ballistic missile programmes in exchange for a gradual easing of sanctions. That stance, however, is challenged by the United States and Japan, which maintain that North Korea must have fully dismantled its weapons programmes before any of the sanctions can be lifted.Moon argued that it was time for a gesture toward Kim."We must assure Chairman Kim that he has made the right decision in committing to denuclearisation," he said."We must encourage North Korea to stay on the path that leads to permanent and solid peace."Second summitUS Secretary of State Mike Pompeo earlier met with his North Korean counterpart Ri Yong Ho in New York and later announced that he will return to Pyongyang next month to push ahead with denuclearisation.Pompeo will also try to arrange a second summit between Trump and Kim, whose meeting in June in Singapore was the first ever between leaders of the two states.Led by the United States, the Security Council last year slapped three rounds of sanctions targeting North Korea's economy with the aim of cutting off sources of revenue for Pyongyang's weapons programme.The United States is facing calls from Russia and China to consider easing sanctions to create an incentive for Pyongyang to move forward.Pompeo on Thursday will address a Security Council meeting on North Korea. Despite the warming of ties, there has been little concrete action towards denuclearisation and there remains scepticism about Kim's intentions.At the last Kim-Moon summit in Pyongyang, the North Korean leader agreed to close a missile test site in the presence of international monitors and offered to shut down the Yongbyon nuclear plant if Washington takes "corresponding measures."