President Donald Trump revived his “Rocket Man” nickname for Kim Jong Un and the threat of military force against North Korea, in the latest sign of rising tensions ahead of Pyongyang’s year-end deadline.

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Trump revisited the name he once used to mock Kim just hours after North Korea said it was preparing a “Christmas gift” for the U.S. if the administration failed to meet its demands by year-end for concessions in nuclear talks. Kim has repeatedly warned in recent months he could take a “new path” in relations with the U.S., while resuming ballistic missile launches.

“He definitely likes sending rockets up, doesn't he? That’s why I call him ‘Rocket Man,’ ” Trump said during the NATO summit in the U.K., adding: “We have the most powerful military we’ve ever had, and we’re by far the most powerful country in the world. And, hopefully, we don’t have to use it, but if we do, we'll use it. If we have to, we'll do it.”

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Despite resuming weapons tests, Kim has refrained from detonating nuclear bombs or launching missiles capable of carrying them to the U.S. while pursuing unprecedented talks with Trump. North Korea’s deadline puts one of Trump’s biggest foreign policy achievements on the line just as he gears up for reelection.

Any shift by Kim could come as soon as the North Korean leader’s annual New Year’s address, which he has previously used to ratchet tensions up and down. The ruling Workers’ Party announced a rare meeting in Pyongyang later this month “to discuss and decide on crucial issues” due to the “changed situation at home and abroad.”

"He definitely likes sending rockets up, doesn't he? That's why I call him 'Rocket Man.' " — President Donald Trump, on North Korea leader Kim Jong Un

While Trump and Kim have held three face-to-face meetings and lavished each other with praise during the last two years, they’ve achieved little beyond a vague promise to “work toward complete denuclearization of the Korean Peninsula.” North Korea has continued to expand a nuclear weapons program that it sees as a vital deterrent against the threat of American invasion.

During their detente, Trump and Kim have held back from the threats and personal insults they flung at each other in 2017 as North Korea conducted a series of weapons tests. The president notably used the “Rocket Man” moniker in September of that year while threatening to “totally destroy North Korea” during a speech to the United Nations. North Korea has referred to Trump as a “dotard.”

Kim has balked at U.S. demands for the dismantling of his weapons program, while Trump has so far rejected North Korea’s calls for greater sanction relief. The most recent working-level talks between the two sides in October broke down, with North Korea’s envoy accusing the American side of arriving “empty-handed.”

Although Kim hasn’t tested an intercontinental ballistic missile in more than two years, he has reminded the region of his growing military threat with tests of shorter-range missiles, including another volley last week. North Korea responded to Japanese Prime Minister Shinzo Abe’s complaints about the launches with a harshly worded commentary, saying he “may see what a real ballistic missile is in the not distant future and under his nose.”

Although North Korean leader Kim Jong Un hasn’t tested an intercontinental ballistic missile in more than two years, he has reminded the region of his growing military threat with tests of shorter-range missiles, including another volley last week.
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Trump also highlighted a key source of friction between the U.S. and its South Korean allies: the president's demands for more military funding. American negotiators walked out of cost-sharing talks in Seoul last month, after South Korea rejected the administration’s demands for as much as a fivefold increase to the approximately $1 billion it pays.

Trump said those talks had made progress, but it wasn't immediately clear whether he was talking about an agreement for the current year or the period ahead.

“Last year, I asked them to pay more, and they agreed,” Trump said. “And nobody knows this — I’ll say it now, I think, for the first time — but they agreed to pay approximately $500 million a year or more for protection.”