MOBARA, Japan — President Donald Trump presented a special Trump trophy to the winner of a sumo tournament in Tokyo on Sunday as he got a taste of one of Japan's most treasured cultural institutions.

The honor given to Trump was part of a charm offensive Japanese Prime Minister Shinzo Abe continued Sunday as he courted the president with three things close to his heart: wrestling matches, cheeseburgers and golf.

Call it sumo diplomacy.

President Donald Trump presents the President's Cup to sumo wrestler Asanoyama during the Summer Grand Sumo Tournament at Ryogoku Kokugikan Stadium in Tokyo on Sunday. Brendan Smialowski / AFP - Getty Images

The president, first lady Melania Trump, Abe and his wife, Akie, joined an estimated 11,500 fans who packed Ryogoku Kokugikan Stadium to watch oversize, muscular men battling in loin cloths.

At the end, Trump stepped into the ring and presented the eagle-topped "President's Cup" to champion wrestler Asanoyama, making him the first American president to participate. Shoes aren't permitted in the sumo ring, but Trump wore dark-colored slippers.

"That was something to see these great athletes," Trump said before dinner at a Hibachi restaurant.

Tonight in Tokyo, Japan at the Ryōgoku Kokugikan Stadium, it was my great honor to present the first-ever U.S. President’s Cup to Sumo Grand Champion Asanoyama. Congratulations! A great time had by all, thank you @AbeShinzo!! pic.twitter.com/nwwxJl6KXH — Donald J. Trump (@realDonaldTrump) May 26, 2019

Trump's four-day state visit to Japan is designed to demonstrate the strength of the bond between the nations. The president received a warm welcome as he arrived at Mobara Country Club, south of Tokyo, for a steamy morning round of golf with the Japanese leader. It was their fifth golf outing.

Abe is pulling out all the stops as he seeks to placate Trump amid growing U.S.-Japan trade tensions and the threat of auto tariffs. Japan is also contending with the continued threat of North Korea and Trump's apparent dismissal of Pyongyang's recent tests of short-range missiles that could reach Japan.

But minus several antagonistic tweets, Sunday was all about bromance and keeping Trump happy.

First it was the golf course, where Trump and Abe played 16 holes, joined by Japanese professional golfer Isao Aoki. Aoki, who is famous for his putting technique, was expected to present Trump with a putter he designed.

Japanese officials said Trump and Abe also had breakfast and lunch together. On the menu for lunch: double cheeseburgers made with U.S. beef.

Next, Abe introduced Trump to Japan's ancient sport of sumo wrestling — something Trump has said he said he finds "fascinating."

The president's attendance at the annual summer sumo tournament in Tokyo may bring back memories of the time he spent promoting the World Wrestling Federation. Trump sponsored major events, appeared in bits, and was inducted into the World Wrestling Entertainment Hall of Fame in 2013.

On Monday, Trump will receive another honor when he becomes the first foreign leader to meet with Japan's new emperor, Naruhito, since he ascended to the throne on May 1.

Trump and Abe will also meet in a more formal setting and participate in a joint news conference. In the evening, Trump will be guest of honor at a banquet hosted by the emperor at Japan's Imperial Palace.

It's all part of a charm offensive that began before Trump took office, when Abe rushed to New York to greet the president-elect at Trump Tower. Japan is deeply dependent on the U.S. for security and Abe has tried to encourage Trump to maintain international agreements and keep up pressure on North Korea.

Golf, in particular, has been a bonding tool for the leaders, who both enjoy a love of the game.

President Donald Trump and Japan's Prime Minister Shinzo Abe playing a round of golf at Mobara Country Club in Chiba. HANDOUT / AFP - Getty Images

"We were able to exchange our views frankly in a cozy atmosphere. It was wonderful," Abe told reporters as he returned to his official residence mid-day.

He told reporters as he left for Mobara that Sunday's weather was great for golf and "it seems we are in a good mood for sumo." He later tweeted a selfie photo of him and Trump, smiling widely on the greens.

Trump tweeted that he'd had "Great fun and meeting with Prime Minister @AbeShinzo," but also continued to stew about domestic politics, claiming that, "Numerous Japanese officials told me that the Democrats would rather see the United States fail than see me or the Republican Party succeed - Death Wish!"

There has long been a tradition of American presidents and candidates holding their tongues about rivals while on foreign soil — but Trump is not one to abide by such norms.

Earlier, Trump had gone after one of his potential Democratic rivals, former President Joe Biden, saying he'd smiled when North Korean leader Kim Jong Un "called Swampman Joe Biden a low IQ individual, & worse."

He also downplayed North Korea's recent series of short-range missile tests. He tweeted that the tests weren't a concern for him — even though they most certainly are for Japan, due to the country's proximity to the North.

"North Korea fired off some small weapons, which disturbed some of my people, and others, but not me," Trump wrote in a message that appeared to undermine his national security adviser, John Bolton, who told reporters Saturday the tests violated U.N. Security Council resolutions.

The president also sought to manage expectations that he and Abe will make significant headway on trade issues when they hold more formal talks on Monday. Trump has been seeking a bilateral trade agreement with Tokyo since he pulled the U.S. out of the multinational Trans-Pacific Partnership trade agreement two years ago, though analysts expect no breakthroughs during Trump's visit.

"Great progress being made in our Trade Negotiations with Japan. Agriculture and beef heavily in play. Much will wait until after their July elections where I anticipate big numbers!" he wrote, referring to Japan's upcoming parliamentary elections.

The Trump administration has been threatening Japan with new tariffs on imports of autos and auto parts on national security grounds. Trump has suggested he will impose tariffs if the U.S. can't wrest concessions from Japan and the European Union.