Top Japanese officials on Friday showed support for U.S. President Donald Trump’s surprise announcement canceling the much-awaited summit meeting with North Korean leader Kim Jong Un in Singapore, saying that holding a meeting should not in itself be a priority in diplomatic exchanges with the nuclear-armed hermit state.

“Having a meeting, itself, is not important. What’s important is to make progress in issues over nuclear weapons, missiles and … the abduction (of Japanese nationals by North Korea),” Chief Cabinet Secretary Yoshihide Suga told a news conference.

“We’d like to maintain close cooperation between Japan and the U.S., and among Japan, the U.S. and South Korea as well,” Suga added.

Several other top Japanese officials — including Foreign Minister Taro Kono and Defense Minister Itsunori Onodera — gave comments almost identical to Suga’s on Friday in separate meetings with reporters, suggesting this was a unified official view that had been prepared in advance.

A high-ranking Japanese official, speaking on condition of anonymity, said he believes Trump’s announcement and the reaction of North Korea is still part of the “negotiations,” with the two countries’ tug-of-war over Pyongyang’s nuclear program continuing.

“I think (Trump) has sent a message that he won’t make any half-way compromise,” the official said.

On Thursday Trump published a letter to Kim, saying he had decided to cancel the planned meeting in Singapore because of “the tremendous anger and open hostility displayed in your most recent statement.”

Earlier the same day, North Korea’s Vice Foreign Minister Choe Son Hui called U.S. Vice President Mike Pence a “political dummy,” warning that Pyongyang could cancel the summit meeting and the U.S. could face “nuclear-to-nuclear showdown.” Her remarks were made in a statement carried by the state-run Korean Central News Agency.

In an apparent response, Trump wrote in the letter: “You talk about nuclear capabilities, but ours are so massive and powerful that I pray to God they will never have to be used.”

Even as the date of the meeting was approaching, Washington and Pyongyang were still reportedly unable to agree on how quickly the North should abandon its nuclear arsenal.

From the beginning many Japan-based experts and diplomats had remained skeptical about Kim’s talk of denuclearization, given Pyongyang’s past records of repeated betrayals, with the country having backed away from deals on which it had agreed.

“I’m not surprised” by Trump’s announcement, said a senior official at the Foreign Ministry on Friday.

“To realize unfaltering denuclearization, you need to do tremendously tough work,” the official also said.

At the same time, Trump sounded considerably — if not unnaturally — friendly to Kim in the letter, leaving the door open for future negotiations to re-arrange a summit meeting.

“I felt a wonderful dialogue was building up between you and me, and ultimately, it is only that dialogue that matters. Some day, I look very much forward to meeting you,” Trump wrote.

“If you change your mind having to do with this most important summit, please do not hesitate to call me or write.”

In response to the letter, North Korean First Vice Foreign Minister Kim Kye Gwan said in a statement that Pyongyang, too, is still willing to talk with the United States.

“We would like to make known to the U.S. side once again that we have the intent to sit with the U.S. side to solve problem regardless of ways at any time,” said Kim in the statement carried by KCNA.

But Mintaro Oba, a former State Department official who worked on North Korean issues, said the letter “certainly makes a return to diplomacy later on much more difficult” although it hasn’t ruled out a future meeting with Kim.

“President Trump and his team seem to be trying to keep a path back to a summit meeting open. But it’s unclear how that can happen unless the two sides come considerably closer together on the denuclearization question or accept a lower bar for success,” he said.

“It’s certainly possible that talk of military options will return to the forefront, and it is definitely a grave concern,” he added.

Ryo Sahashi, professor of international politics at Kanagawa University, also noted that the United States has left a path open for a possible return to a summit.

“Looking at the letter, it’s apparent that Trump hasn’t given up on the negotiation. It says ‘someday, I look very much forward to meeting you,’ written in Trump’s own tone of voice,” Sahashi said.

“It would be a huge achievement for Trump” to hold a successful summit with North Korea, he added.

“I think that’s why Trump is leaving open the possibility.”

The letter was published just hours after North Korea gave foreign journalists an opportunity to watch what Pyongyang claimed was destruction of tunnels at the Punggye-ri nuclear test site in the country’s northeastern region.

However, Pyongyang didn’t fulfill a reported promise to invite nuclear arm experts to the site, leaving few means for the U.S. and other countries to verify Pyongyang’s claim that the nuclear test tunnels were totally destroyed.

Staff writer Jesse Johnson contributed to this report.