U.S. President Donald Trump on Tuesday hinted at using his country's military might against North Korea if necessary, while emphasizing his "good relationship" with leader Kim Jong Un.

"Now we have the most powerful military we have ever had and we are by far the most powerful country in the world, and hopefully we do not have to use it. But if we do, we will use it. If we have to, we will do it," Trump told reporters in London.

Trump, meanwhile, said, "I have a very good personal relationship" with Kim, adding, "I am possibly the only one he has that kind of relationship with in the world."

The U.S. president is visiting the British capital to attend a summit of the North Atlantic Treaty Organization.

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