Donald Trump\u00a0has pledged to meet the North Korean leader, Kim Jong-un, \u201cin the coming weeks\u201d but warned that he was prepared to walk away if the talks were not \u201cfruitful\u201d.\r\n\u201cAs you know, I will be meeting with\u00a0Kim Jong-un\u00a0in the coming weeks to discuss the denuclearisation of the Korean peninsula,\u201d the US president told reporters at his Mar-a-Lago estate in Florida. \u201cHopefully that meeting will be a great success and we\u2019re looking forward to it.\u201d\r\nThere has never been a summit between a sitting US president and a North Korean leader, though Bill Clinton came close to agreeing to meet Kim\u2019s father, Kim Jong-il, in late 2000.\r\nEarlier on Tuesday, Trump confirmed that Mike Pompeo, the CIA director,\u00a0had travelled to North Korea to meet Kim, paving the way for Trump to hold a historic summit that has eluded his predecessors.\r\n\r\nThe mission, which came shortly after Pompeo was nominated as secretary of state, was the highest-level meeting between the two countries since 2000, when Madeleine Albright-met Kim Jong-il, Kim\u2019s father, in Pyongyang. It also marked the first time the previously reclusive\u00a0Kim Jong-un\u00a0has met a senior western official.\r\nSpeaking at a joint press conference with the Japanese prime minister, Shinz\u014d Abe, the president said: \u201cWe\u2019ve never been in a position like this with that regime, whether it\u2019s father, grandfather or son, and I hope to have a very successful meeting. If we don\u2019t think it\u2019s going to be successful, we won\u2019t have it, we won\u2019t have it. If I think that it\u2019s a meeting that is not going to be fruitful, we\u2019re not going to go.\r\n\u201cIf the meeting when I\u2019m there is not fruitful, I will respectfully leave the meeting and we\u2019ll continue what we\u2019re doing or whatever it is that we\u2019ll continue, but something will happen.\u201d\r\nTrump also said the US was \u201cfighting very diligently\u201d to win freedom for\u00a0three Americans detained in North Korea. He said he believed there was a \u201cgood chance of doing it\u201d and that \u201cwe\u2019re having a good dialogue\u201d with the North Koreans.\r\nThe Chinese president,\u00a0Xi Jinping, had had a \u201cbig impact\u201d on the North Korean situation, Trump added, though there was potential to do more. He claimed that South Korea had credited him with preventing its winter Olympics from being \u201ca total failure\u201d. He said he hoped to see the day when the two Koreas can live together in \u201csafety, prosperity and peace\u201d.\r\nAbe said there should be \u201cno reward\u201d given to\u00a0North Korea\u00a0just because the isolationist country was responding to dialogue over its development of nuclear weapons, adding that \u201cmaximum pressure should be maintained\u201d.\r\n\r\nThe key question at any summit between Trump and Kim Jong-un is whether the North Korean leader is serious about dismantling his regime\u2019s nuclear weapons and missiles programme \u2013 and what he would demand from the US in return.\r\nTrump also said he had made \u201ca promise\u201d to Abe to help return the Japanese captives believed held by the regime. The abductees were \u201cone of the truly most important things on Shinz\u014d\u2019s mind\u201d, he added, and he wanted \u201cto see these families reunited as soon as possible\u201d.\r\nTrump was asked if he had ruled out firing the special counsel\u00a0Robert Mueller\u00a0or the deputy attorney general, Rod Rosenstein. He replied: \u201cThere was no collusion and that has been so found, as you know, by the House intelligence committee. There was no collusion with Russia other than by the Democrats, or as I call them the obstructionists.\r\n\u201cThis was really a hoax created largely by the Democrats. There has been no collusion. They won\u2019t find collusion. It doesn\u2019t exist.\u201d\r\nFinally addressing the question of Mueller and Rosenstein, he added: \u201cThey\u2019ve been saying I\u2019ve been going to get rid of them for the last three months, four months, five months and they\u2019re still here \u2026 We want to get the investigation over with, done with. Get it behind us.\u201d\r\nTrump pointed to his recent actions in Syria and reiterated his claim: \u201cThere\u2019s been nobody tougher on Russia than President Donald Trump.\u201d But he argued this did not fit the media\u2019s narrative.