CNN  — 

Donald Trump will visit Japan twice in the coming months, a US official told CNN.

The US president will pay a formal visit to the close ally in late May, likely to Tokyo, after the country’s current crown prince Naruhito becomes Japan’s 126th Emperor.

Trump will then return in late June to attend the G20 in Osaka, the official said.

The news comes ahead of Trump’s upcoming summit with North Korean leader Kim Jong Un in Hanoi, which is set to take place next week.

Trump spoke with Japan Prime Minister Shinzo Abe over the phone on Wednesday to coordinate their policies on North Korea’s nuclear development, a Japanese official said.

US President Donald Trump (R) and Japanese Prime Minister Shinzo Abe shake hands at the White House, on June 7, 2018 in Washington, DC.

During the call, Abe again asked Trump to raise the issue of Japanese abductees with Kim, a repeated concern for Tokyo. It was not addressed in depth at Trump and Kim’s first summit in Singapore, last year.

Since his inauguration in January 2017, Trump has built a close relationship with Abe, lavishing him with compliments. Japan was the first Asian country that Trump visited after taking power.

On Friday, Trump said Abe had nominated him for a Nobel Peace Prize with a five-page letter.

“Prime Minister Abe of Japan gave me the most beautiful copy of a letter that he sent to the people who give out a thing called the Nobel Prize,” he said, presumably referring to the Norwegian Nobel Committee.

“He said ‘I have nominated you, respectfully, on behalf of Japan. I am asking them to give you the Nobel Peace Prize,” added Trump.

When questioned in the Japanese Parliament on Monday, Abe politely declined to confirm whether or not he had nominated Trump.

In November, after the Republican Party’s widespread losses in the US midterm elections, Abe congratulated Trump on his “historic victory.”