President Donald Trump on Sunday issued a stern warning that "no dictator" should underestimate the United States as he started an Asian tour dominated by the North Korea nuclear crisis. Speaking to cheering military personnel at Yokota Air Base just west of Tokyo minutes after landing, Mr Trump donned a bomber jacket and said, "No one, no dictator, no regime and no nation should underestimate … American resolve. Every once in a while in the past, they underestimated us. It was not pleasant for them, was it? "We will never yield, never waver and never falter in defence of our people, our freedom and our great American flag." Mr Trump's marathon trip comes with the North Korea crisis at fever pitch, as US bombers fly sorties over the Korean peninsula and fears mount of another Pyongyang missile test. According to the <em>Washington Post</em>, Pentagon officials have warned that the only way to locate and secure North Korea's nuclear weapons sites would be via a ground invasion. <strong>_______________</strong> <strong>President Trump in Japan</strong> North Korea itself welcomed Mr Trump to the region with a rhetorical volley via the ruling party newspaper <em>Rodong Sinmun</em>, warning a "spiritual instable" president against making "reckless remarks". <strong>North Koreans 'great people'</strong> The president's first stops are Japan and South Korea — frontline US allies in the effort to force Pyongyang to abandon its nuclear programme, and the two countries with most to fear should a full-scale conflict break out. Mr Trump touched down under clear blue Tokyo skies and stepped out with his wife Melania in bright sunshine to greet the crowds. Speaking to reporters on Air Force One, he announced he would probably be meeting Russian president Vladimir Putin during the tour, as the international community scrambles for a solution to the North Korean crisis. "I think it's expected we'll meet with Putin, yeah. We want Putin's help on North Korea, and we'll be meeting with a lot of different leaders," said Mr Trump. He added that North Korea was a "big problem for our country and for the world, and we want to get it solved" but had kind words for its people. "I think they're great people. They're industrious. They're warm, much warmer than the world really knows or understands. They're great people. And I hope it all works out for everybody," he said. He told reporters earlier that a decision would be made soon on whether to add reclusive North Korea to a list of state sponsors of terrorism, saying his administration planned to take a different approach after years of what he termed "total weakness." The next stop was a golfing date with his "friend" Shinzo Abe, prime minister of Japan. The two leaders have struck up an unlikely but easy rapport and the Japanese prime minister welcomed his American guest with an effusive display of friendship. The two leaders first enjoyed a leisurely, casual lunch at <span>Kasumigaseki</span> Country Club before taking striding out on to the fairway to play nine holes, for which they were joined by one of the world's top professional golfers, <span><span>Hideki</span></span> Matsuyama. Mr Trump joked with reporters on Air Force One that they should not believe him if he claims to outhit Hedeki Matsuyama, one of the world's best players who joined the leaders on the course. Mr Abe also appeared to have enjoyed his nine holes, tweeting: "A round of golf with a marvellous friend (president Donald J Trump), full of spirited conversation." The two leaders, and their wives, were having an intimate dinner on Sunday night. Arriving at the upmarket restaurant where they were to dine on grilled Japanese premium beef, Mr Trump said US-Japan ties were closer than ever. "We’ll have dinner tonight. I think we’ll insult everybody by continuing to talk about trade," he said. But this easy-going, low-key beginning was paving for the high-stakes diplomacy in the coming days, with formal talks, a press conference and state dinner planned in Tokyo for Monday. The Japanese leader has emerged strengthened from a crushing victory in a snap election and has firmly supported Mr Trump in his policy of exerting maximum pressure on Mr Kim, backed up with the threat of military force. "I want to further cement the bond of the Japan-US alliance, based on our relations of trust and friendship with president Trump," Mr Abe said as Mr Trump arrived. Mr Trump for his part described Japan as a "treasured partner and crucial ally of the US". "Trump only has to play golf in Japan, as he knows Japan will follow [the US] whatever happens. Everything has been sorted out beforehand," said Tetsuro Kato, political scientist at Tokyo's Hitotsubashi University. <strong>'Appeasement'</strong> After Japan, Mr Trump travels to Seoul, where his relationship with President Moon Jae-in is noticeably cooler. While Mr Trump has been in regular contact with the hawkish Mr Abe during the North Korean crisis, he pointedly failed to speak to Mr Moon for several days after Pyongyang's second intercontinental ballistic missile test in July. Mr Trump labelled Mr Moon's more conciliatory approach to North Korea as "appeasement" on Twitter, a comment that did not go down well in Seoul's presidential Blue House. Mr Trump will speak to South Korean MPs but not follow the well-trodden path to the Demilitarised Zone dividing the Korean peninsula — a visit derided in Washington as a bit of a "cliché". From Seoul, Mr Trump travels to China to meet his counterpart Xi Jinping who, like Mr Abe, has solidified his grip on power after being handed a second term. _______________ <strong>Read more</strong> _______________ Mr Trump said before his trip that China could have a "big problem" with "warrior nation" Japan if the North Korea issue is not solved. He then travels to a Pacific Rim summit in Vietnam before heading to a gathering of Southeast Asian leaders. Some observers have fretted that a gaffe by the famously unscripted president could send tensions rising on the peninsula. "It will be a disaster if he speaks off the cuff and without thinking," said Professor Koo Kab-woo from the University of North Korean Studies in Seoul. "If Trump says anything that can provoke North Korea, it could send military tensions soaring again."