President Donald Trump set foot in North Korea on Sunday, becoming the first US leader to do so, and came away with an agreement to resume talks on denuclearisation of the Korean peninsula after meeting North Korean leader Kim Jong-un. Mr Trump and Mr Kim, meeting for the third time in the space of a year, greeted each other warmly after crossing the open ground of the demilitarised zone (DMZ) separating North and South Korea. “Stepping across that line was a great honour, a lot of progress has been made,” Mr Trump told the assembled press after Mr Kim accompanied him back into the South Korean side of the de-militarised zone. Mr Trump and Mr Kim then held a closed-door meeting for nearly an hour. "We just had a very, very good meeting," the US president said after the talks. "We'll see what can happen." He said both sides would set up teams to push forward stalled talks aimed at getting North Korea to give up its nuclear weapons, adding "speed is not the thing". Mr Trump thanked Mr Kim for meeting him, saying that if the North Korean leader had not shown up the press would have made him look bad after his public invitation to talk on Twitter. Mr Kim said he had been surprised by Mr Trump's last-minute invitation to meet at the DMZ on Sunday, but said it “can be the foundation for better things in the future”. The leaders last met at a failed summit in Vietnamese capital Hanoi in February. Mr Trump abruptly left that meeting without a joint press conference. Since then there has apparently been little public movement in the talks for North Korea to abandon its nuclear programmes. Mr Kim looked relaxed and smiled as he chatted with Mr Trump on Sunday amidst a throng of press photographers, aides and bodyguards. Mr Trump said the two leaders "moved mountains" to arrange the last-minute meeting. South Korean President Moon Jae-in praised the two leaders for “being so brave” and said: “I hope President Trump will go down in history as the president who achieves peace on Korean Peninsula.” Mr Kim said it would be a great honour if Mr Trump visited his capital of Pyongyang. The two agreed to visit each other's country "at the right time", Mr Trump said. The meeting even drew praise from Pope Francis during his weekly address in Rome's St Peter's Square. "I salute the protagonists, with a prayer that such a significant gesture will be a further step on the road to peace, not only on that peninsula, but for the good of the entire world," he said. The meeting came about after a tweet in which Mr Trump expressed his desire to be the first sitting US president to cross into North Korea when made his first trip to the DMZ. “I look forward to saying hello to him if that all finally works out,” Mr Trump said. “I guess there’s always a chance that it might not, but it sounds like the teams would like to have that work out, so that’s good.” Mr Trump made his audacious offer to meet Mr Kim at the DMZ while heading to South Korea after attending the Group of 20 summit in Osaka, Japan. A top North Korean diplomat, Choe Son Hui, offered a sign of encouragement when she called Mr Trump’s tweet “a very interesting suggestion” in a statement on Saturday. But there was suspense throughout meetings on Sunday morning, as Mr Trump and Mr Moon both appeared unsure about whether Mr Kim would appear. The US president repeatedly cautioned that the logistics were complicated, and he said that any meeting would be little more than a photo op. “Chairman Kim wants to do it,” he said before an official meeting with Mr Moon. “A handshake means a lot,” he added. Mr Moon,who has acted as an intermediary in negotiations between Mr Trump and Mr Kim, praised Mr Trump's initiative. “I saw that tweet and it felt like you’ve sent a flower of hope for the Korean Peninsula,” Mr Moon told Mr Trump on Sunday. “If you shake hands with Chairman Kim Jong-un at the Military Demarcation Line, it would be historic, just by the picture of it. Not only for the denuclearisation of the Korean Peninsula, but also for a permanent peace in the region, it’ll be very meaningful.” <strong>March 7, 2018:</strong> A special South Korean envoy returns from visiting Pyongyang and says Mr Kim is willing to discuss the future of his nuclear arsenal with Washington. Days later, Mr Trump accepts Mr Kim's invitation to meet. <strong>April 21, 2018:</strong> North Korea says it has suspended nuclear and long-range missile tests and is shifting its focus to improving its economy. Mr Trump tweets the move is "big progress!" <strong>May 9, 2018:</strong> US Secretary of State Mike Pompeo visits Pyongyang to prepare for the planned Trump-Kim meeting. North Korea frees three Americans who had been imprisoned. <strong>June 12, 2018:</strong> Mr Trump and Mr Kim meet in Singapore for the first summit between the leaders of the United States and North Korea since the end of the 1950-53 Korean War. Mr Kim vows to work towards achieving complete denuclearisation of the Korean Peninsula. <strong>January 1, 2019:</strong> Mr Kim in his New Year's Day speech says he hopes to continue his nuclear summitry with Mr Trump, but also that he would seek a "new way" if the United States persists with sanctions and pressure against North Korea. <strong>February 27-28, 2019: </strong>Mr Trump and Mr Kim meet in Hanoi, Vietnam, for their second summit. The meeting collapses with reaching any agreement after Mr Trump rejects Mr Kim's calls for major sanctions relief in return for dismantling his main nuclear complex in a partial denuclearisation step. <strong>April 13, 2019:</strong> Kim says he is open to another meeting with Mr Trump, but sets the year's end as a deadline for Washington to offer mutually acceptable terms for an agreement to salvage the diplomacy. <strong>May 9, 2019:</strong> North Korea fires two short-range missiles towards the sea in its second launch in five days, ending a pause in ballistic testing. The launches are seen as measured efforts to dial up pressure on Washington and Seoul without actually causing the negotiations to collapse. <strong>June 29, 2019: </strong>In a tweet message, Mr Trump invites Mr Kim to shake hands during his planned visit to the Korean Demilitarized Zone. Mr Kim's vice foreign minister, Choe Son Hui, calls Mr Trump's offer "a very interesting suggestion." <strong>June 30, 2019:</strong> Mr Trump shakes hands with Mr Kim at a jointly controlled area inside the DMZ and becomes the first US president to cross over into North Korean territory. Mr Kim then walks over the demarcation line into South Korea with Mr Trump.