President Donald Trump needled Japan over the US-Japan trade imbalance as he kicked off a state visit to the country Saturday that's been tailor-made to his whims and ego. Speaking at a reception with several dozen Japanese and American business leaders at the US ambassador's residence in Tokyo shortly after his arrival, Mr Trump said the US and Japan "are hard at work" negotiating a new bilateral trade agreement that he said would benefit both countries. "I would say that Japan has had a substantial edge for many, many years, but that's OK," Mr Trump told the group, joking that, "Maybe that's why you like me so much." The comments underscored the competing dynamics of a state visit designed to show off the deep ties between the US and Japan and the close friendship between Mr Trump and Japanese Prime Minister Shinzo Abe, even as tensions are high. Mr Abe has rolled out the carpet for Mr Trump as part of a continued charm offensive, giving him the honour of being the first head of state invited to meet Emperor Naruhito since he ascended to the throne on May 1. Mr Trump will also play golf with Mr Abe and have the chance to present a "Trump Cup" at a sumo wrestling championship Sunday. While the visit is expected to be largely ceremonial, the stakes are also high. Mr Trump is threatening Japan with potentially devastating US tariffs on foreign autos and auto parts, and has suggested he will go ahead with the tariffs if US Trade Representative Robert Lighthizer doesn't manage to wrest concessions from Japan and the European Union. Mr Trump had predicted that a US-Japan trade deal could be finalised during his trip. But that's highly unlikely given the two sides are still figuring out the parameters of what they will negotiate. Mr Trump nonetheless painted the negotiations positively as he addressed the business group shortly after touching down in Japan following a 14-hour flight. "With this deal we hope to address the trade imbalance, remove barriers to United States exports and ensure fairness and reciprocity in our relationship. And we're getting closer," he said, while urging the business leaders to invest more in the US. He also praised what he described as the "very special" US-Japan alliance, telling the group that, "The relationship with Japan and the United States, I can say for a fact, has never been stronger, it's never been more powerful, never been closer." It was the kind of talk expected during a trip meant to highlight the alliance between the countries and the friendship between their leaders. "In the world of Donald Trump, terrible things can happen if you're an ally, but no major blows have landed on Japan," said Michael Green, senior vice president for Asia and Japan chair at the Centre for Strategic and International Studies. Mr Trump has the honour of being the first head of state invited to meet Emperor Naruhito since he assumed power after his father stepped down, the first abdication in about two centuries. Emperor Naruhito will welcome Trump to the Imperial Palace on Monday for a meeting and banquet in his honor. "With all the countries of the world, I'm the guest of honor at the biggest event that they've had in over 200 years," Trump said on Thursday. Mr Trump will also be golfing with Mr Abe on Sunday and hanging out that much-ballyhooed sumo trophy, which the White House said will stand nearly 1.5 metres and weigh between 27 and 32 kilograms. Behind the smiles and personal friendship, however, lurks deep uneasiness over Trump's threat to impose tariffs on Japanese autos and auto parts on national security grounds, a move that would be far more devastating to the Japanese economy than earlier tariffs on steel and aluminum. Mr Trump recently agreed to a six-month delay, enough time to carry Abe past July's Japanese parliamentary elections.