U.S. President Donald Trump on Thursday said the country’s military was “ready if necessary” after pulling out of a planned summit with North Korean leader Kim Jong Un originally scheduled for June 12.

Making his first statement after his letter to Kim announcing the cancellation was released earlier in the day, Trump also said that he had spoken to allies in the region.

“I have spoken to General Mattis, and the Joint Chiefs of Staff, and our military which is by far the most powerful anywhere in the world … is ready if necessary,” Trump said in prepared remarks.

“Likewise I have spoken to South Korea and Japan, and they are not only ready should foolish or reckless acts be taken by North Korea, but they are also willing to shoulder much of the cost of any financial burden, any of the costs associated by the United States in operations if such an unfortunate situation is forced upon us.”

Trump reiterated that he believed North Korea would greatly benefit from giving up its nuclear weapons, though added that Washington would accept nothing less than full denuclearization.

“That bright and beautiful future can only happen when the threat of nuclear weapons is removed. No way it can happen otherwise,” Trump told assembled reporters.

As in his letter to Kim, the president seemed to leave the door open for the summit to occur, either on June 12 or at a later date.

“And hopefully everything is going to work out well with North Korea, and a lot of things can happen … It’s possible that the existing summit could take place, or a summit at some later date. Nobody should be anxious, we have to get it right.”

The U.S. President also cryptically added that he knew what caused the negotiations to break down, though declined to share the information.

“So the dialogue was good until recently, and I think I understand why that happened,” Trump said in response to a question from the media.

“And I won’t say that. Someday I’ll give it to you, you can write about it in a book.”

Trump’s surprise decision to withdraw from what would have been the first meeting between a sitting U.S. president and a North Korean leader comes just hours after the DPRK claimed to have dismantled its nuclear testing site at Punggye-ri.

But talks between the two sides appeared to have stalled recently, with North Korea threatening to pull out of the negotiations on May 15.

And while inter-Korean negotiations are also in limbo, South Korean President Moon Jae-in on Friday urged Washington and Pyongyang to communicate with each other.

“Denuclearization of the Korean Peninsula and the establishment of permanent peace are historic tasks that can neither be abandoned nor delayed,” Moon said during an emergency meeting with security advisers in comments carried by Yonhap.

“I am very perplexed and it is very regrettable that the North Korea-U.S. summit will not be held on June 12 when it was scheduled to be held.”

Additional reporting by Colin Zwirko

Featured Image: Donald Trump by Gage Skidmore on 2016-10-04 15:09:17