On Thursday, it was announced that President Donald Trump was calling off his planned summit with North Korean Leader Kim Jong Un. This meeting was meant to quell the impending threat of nuclear war, but for now, those hopes have been cast aside.

In a letter addressed to Kim Jong Un, President Trump explains that his decision to pull the United States out of the approaching talks came as a result of recent aggressive statements made by the North Korean regime, which Trump characterized as “openly hostile.” The president went on to write.

Sadly, based on the tremendous anger and open hostility displayed in your most recent statement, I feel it is inappropriate, at this time, to have this long-planned meeting … If you change your mind having to do with this most important summit, please do not hesitate to call me or write … The world, and North Korea in particular, has lost a great opportunity for lasting peace and great prosperity and wealth. This missed opportunity is a truly sad moment in history.”

In the letter, Trump went on to praise Kim’s release of American prisoners held in North Korea as “beautiful gesture,” and said it was “very much appreciated.” He also expressed his wishes for Kim and his regime to “change their mind” and engage in the diplomatic talks in good faith but not all the rhetoric within the letter contained overtures of peace. As Defense Secretary James Mattis has repeatedly said in recent months, American diplomacy must be backed by the capability to use military force when it’s required, and Trump took the opportunity to remind Kim about just how much of that force is at his disposal.