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.

“You talk about your nuclear capabilities,” Trump wrote, “but ours are so massive and powerful that I pray to God they will never have to be used.”

It’s likely that the letter was prompted not specifically by a statement made by Kim, but by one made by a senior official within his regime. After weeks of simmering tensions between North Korea and the United States, Choe Son Hui, a vice-minister in the North Korean Foreign Ministry, told North Korean media that her nation may need to reconsider their participation in the talks because of American aggression.

“Whether the U.S. will meet us at a meeting room or encounter us at nuclear-to-nuclear showdown is entirely dependent upon the decision and behavior of the United States,” Choe said on Thursday. She was spurred by statements made by Vice President Mike Pence and others within the Trump administration that, among other things, compared North Korean denuclearization to a similar endeavor in Libya, which resulted in the toppling of the state government and the brutal killing of Libyan leader Muammar Gaddafi at the hands of his people.

The question on everyone’s mind now is, of course, what’s next? After months of buildup, it seemed tensions on the Korean peninsula had finally begun to wane — and just in time for a rise in tensions between the United States and another aggressive state with nuclear ambitions, Iran. Now, President Trump finds himself embroiled in not one, but two nuclear staring contests that could both potentially lead to significant conventional conflicts, let alone the possibility for nuclear ones.