U.S. President Donald Trump expressed hope Saturday of deeper economic ties with Japan in the nation's new imperial era of Reiwa, as he started a four-day state visit that will make him the first foreign leader to meet with new Emperor Naruhito.

"It's my sincere hope that in the Reiwa era the economic ties between the United States and Japan continue to grow deeper and stronger, if that's possible," Trump said in a meeting with Japanese business leaders in Tokyo, the first of a series of events including an audience with the emperor and Empress Masako on Monday.

In a separate meeting on Monday, Trump and Prime Minister Shinzo Abe are expected to affirm coordination in arranging a first-ever summit between Japan and North Korea.

In recent weeks, Abe has repeatedly expressed his readiness to meet with leader Kim Jong Un without preconditions in a bid to resolve the issue of North Korea's abductions of Japanese nationals in the 1970s and 1980s.

Trump's itinerary also includes a golf outing, a visit to a grand sumo tournament and an informal dinner with Abe, programs meant to highlight the leaders' close relationship and the firmness of the bilateral alliance.

In the Abe-Trump summit, the leaders are likely to underscore that Tokyo and Washington aim to achieve full denuclearization of North Korea in partnership with the international community, according to sources familiar with bilateral relations.

Abe will ask that Trump back efforts to set up a meeting with Kim. Abe plans to tell Trump that if he were to meet Kim, he would raise not only the abduction issue but the nuclear issue, the sources said.

Speaking in Tokyo on Saturday, U.S. national security adviser John Bolton said North Korea's launch of short-range ballistic missiles earlier this month was a violation of U.N. Security Council resolutions, but that Washington is open to talks with Pyongyang.

Referring to Abe's preparedness to meet Kim without preconditions, Bolton told reporters that such talks should contribute to efforts toward North Korea's denuclearization and resolution of the abduction issue.

(Security is tightened at Tokyo's Haneda airport on May 24, 2019, a day before U.S. President Donald Trump's scheduled arrival in Japan.)

Following the talks with Abe, Trump will meet with relatives of abduction victims. The president raised the abduction issue during the first-ever U.S.-North Korea summit last June in Singapore and also in his second meeting with Kim in February in Hanoi.

Besides North Korea, Abe and Trump are expected to focus on bilateral trade, with Trump pushing Japan to cut its hefty and chronic trade surplus with the United States.

Similarly, American farmers have grown concerned about their reduced market share in Japan following the enforcement in December of a revised Trans-Pacific Partnership, an 11-nation free trade agreement that includes Japan and farming nations such as Australia and Canada.

In an address to the business leaders, Trump said that through negotiations for a Japan-U.S. trade agreement, he wants to make bilateral trade "a little bit more fair," alluding to the U.S. trade deficit with Japan.

"With this deal, we hope to address the trade imbalance, remove barriers to United States exports, and ensure fairness and reciprocity in our relationship," he said.

"Japan has had a substantial edge for many, many years, but that's OK, maybe that's why you like us so much."

Tweeting from Air Force One en route to Japan on Friday with first lady Melania, Trump said he is "looking forward to honoring, on behalf of the United States, His Majesty, the Emperor of Japan," and that he will discuss trade and regional security with Abe, whom he called "my friend."

Emperor Naruhito ascended the Chrysanthemum Throne on May 1 after former Emperor Akihito abdicated the previous day, the first Japanese monarch to stand down in about 200 years.

On Tuesday, Abe and Trump will board the Japanese Maritime Self-Defense Force helicopter carrier Kaga docked at an MSDF base in Yokosuka, south of Tokyo, in another demonstration of the firmness of the Japan-U.S. alliance.

Trump will address troops during a visit to the U.S. Yokosuka Naval Base before wrapping up the trip.

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