US President Donald Trump said Friday that a date and venue for his landmark summit with North Korea's Kim Jong Un would be unveiled soon, as anticipation builds for the unprecedented talks between the mercurial leaders. And while Trump said he was not envisaging a drawdown of troops in South Korea for now -- something the regime in Pyongyang has long wanted -- he admitted it was a possibility in the longer term. Since Kim met with South Korean President Moon Jae-in, Trump has been steadily offering tidbits about his expected meeting with the North's ruler -- even hinting that three Americans imprisoned there could soon be freed. "We now have a date and we have a location, we'll be announcing it soon," Trump told reporters on Friday about his summit, as he left the White House on a trip to Texas. The US president suggested earlier this week that the Demilitarized Zone between the two Koreas -- scene of the historic Kim-Moon talks -- could also be an appropriate venue for his own meeting with Kim. Other possible sites reportedly include Singapore, Mongolia and Switzerland. Preparations for a Trump-Kim meeting have gained momentum since the Korean summit a week ago, which saw Pyongyang and Seoul promise to pursue the complete denuclearization of the peninsula and a permanent peace. North Korea has offered to close its nuclear test site this month -- and invited US experts to verify the move. Other less dramatic but notable signs of rapprochement have emerged almost daily, including North Korea moving its clocks forward by 30 minutes early Saturday to match time with the South. - Troops 'not on the table' - As for a reduction in the number of troops stationed in South Korea, Trump said that was not under negotiation -- for now. "We haven't been asked it," he said. "I think a lot of great things will happen. But troops are not on the table. Absolutely." The US president added, however: "Now I have to tell you, at some point into the future, I would like to save the money. You know, we have 32,000 troops there." US National Security Advisor John Bolton earlier denied as "utter nonsense" a New York Times report saying Trump had asked the Pentagon for options to prepare for drawing down the 28,500-strong US force. The Times report, which cited several unidentified officials briefed on the deliberations, said reduced troop levels were not intended to be a bargaining chip in Trump-Kim talks. But officials acknowledged that a peace treaty between the two Koreas -- technically still at war since the 1950s, with only an armistice in place -- could diminish the need for the US forces, The Times said. - 'Stay tuned' on US prisoners - Trump, who has hinted at imminent news about three Americans detained in North Korea, once more sounded an upbeat note regarding their fate. "We're having very substantive talks with North Korea and a lot of things have already happened with respect to the hostages," he said. "As I said yesterday, stay tuned," Trump added. "I think you will be seeing very, very good things." The United States has been demanding the North free Kim Hak-song, Kim Sang-duk and Kim Dong-chul and reports have said the two sides were close to reaching a deal on their release. Plans for a Trump-Kim summit follow months of tense saber-rattling over Pyongyang's testing of atomic weapons and long-range missiles, including some theoretically capable of reaching the American mainland. But a spectacular detente in recent months has fed hopes of a historic turning point in the region. Several new steps reflect the harmonious atmosphere between the two Koreas. After their united women's hockey team captured hearts at this year's Olympics, the two Koreas joined forces this week at the world table tennis championships in Sweden rather than play each other in the semi-finals. On Friday the Koreans lost to Japan in the finals. Also on Friday the International Civil Aviation Organization said North Korea had asked for permission to open an air corridor between Pyongyang and Incheon, near Seoul, a move the UN agency expressed a "willingness" to facilitate. Given the progress on multiple fronts, Trump exulted before a crowd at a National Rifle Association meeting in Dallas later Friday. "We're really doing well with North Korea," he said, adding that he had agreed to temper his rhetoric -- such as branding Kim Jong Un a "Rocket man" and threatening "fire and fury" last year as nuclear tensions spiked. "Now I'm trying to calm it down a little bit," Trump said.