The president of the United States on Sunday had his first informal talks with the Japanese prime minister during a round of golf in southeast Tokyo as trade talks between the two nations got underway.

Although the winner of the round between Shinzo Abe and Donald Trump was not reported, the Japanese Ministry of Foreign Affairs said it was played at Mobara Country Club and started at 9.45am local time, lasting two and a half hours. The course is situated in Chiba prefecture, an area that was hit by a moderate earthquake ahead of Trump's arrival Saturday.

The pair was joined on the course by veteran Japanese golfer Isao Aoki.

Abe and Trump "deepened their friendship amid a cozy atmosphere," according to the ministry.

Alongside a selfie taken with Trump on the course, Abe said in a tweet Sunday that he "would like to make the Japan-U. S. alliance even more unwavering in the new Japanese era." The new Reiwa era of Japan began on May 1 with the ascension of Emperor Naruhito to the throne.

“Great fun and meeting with Prime Minister @AbeShinzo. 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!” Trump tweeted.

Before the 16 holes, the two leaders had breakfast and afterwards had lunch consisting of double cheeseburgers with beef from the United States, the foreign ministry said.

Both wearing caps, Abe took the wheel of the golf cart they traveled in.

Meanwhile, the US leader also reported that “great progress (was) 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 added, referring to Japan’s House of Councillors polls to elect 124 of 245 upper house members for a six-year term.

In the negotiations between US Trade Representative Robert Lighthizer and his Japanese counterpart Toshimitsu Motegi, the US is reportedly seeking greater access to the Japanese market in beef, pork and wheat products, among others.

Japan is expanding its markets in those sectors with products from Australia or New Zealand, thanks to the Trans-Pacific Partnership (TPP), from which the Trump administration withdrew.

Tokyo is reportedly calling for lower US tariffs on Japanese industrial products, including vehicles - one of its main exports.

Later Sunday, Trump is due to attend the final of a sumo wrestling tournament, where the US president will present a trophy to the winner.

The two leaders will then meet again over dinner with their respective wives, Akie Abe and Melania Trump, ahead of formal meetings on Monday, during which Trump will also be the first foreign leader to meet Emperor Naruhito.

Earlier Sunday, Trump had reiterated his “confidence” in North Korean leader Kim Jong-un after Pyongyang's missile tests earlier in the month. Trump's stance was in direct contrast to his own national security adviser and host country Japan.

“North Korea fired off some small weapons, which disturbed some of my people, and others, but not me. I have confidence that Chairman Kim will keep his promise to me,” Trump tweeted, apparently referring to what he has reported as a pledge by Kim to freeze the testing of missiles and nuclear weapons.

A day earlier, US National Security Adviser John Bolton said there was “no doubt" the ballistic missile launches violate UN Security Council resolutions. It’s a view also adopted by Tokyo.

Trump’s four-day visit began Saturday, welcomed by the Tokyo Skytree lit up in the Stars and Stripes.

It is the US president’s second state trip to Japan, after a visit in Nov. 2017, and it will end on May 28.

Abe and Trump have held 38 summit talks, including over the phone, during Trump’s term.