UNITED NATIONS — President Donald Trump’s threat before the world to obliterate North Korea left no doubt about his determination to stop the communist country’s nuclear weapons buildup. His disparagement of the Iran nuclear deal in the same speech offered Pyongyang little hope of a negotiated solution.

In his maiden address at the U.N. General Assembly on Tuesday, Trump spelled out in blunt and personal terms the reasons why Kim Jong Un and his government should be treated as pariahs. It was a surprisingly brutal indictment, even by the standards of a president who has spoken about unleashing “fire and fury” on Kim’s country if it didn’t end its nuclear provocations.

Trump said not only has the North Korean government starved its citizens and killed opponents, it was now threatening the world with “unthinkable loss of life.”

“It is time for North Korea to realize that the denuclearization is its only acceptable future,” Trump said. He offered no path toward making that future a reality.

Despite Trump’s rhetoric, his administration insists it is seeking a diplomatic resolution. Any military intervention designed to eliminate the North’s nuclear and missile arsenal would almost surely entail dire risks for U.S. allies in the region, particularly South Korea, lying in range of the North’s vast stockpiles of weaponry.

Asked about Trump’s address, Defense Secretary Jim Mattis reiterated his preference Tuesday.

“We will hopefully get this resolved through diplomatic means,” Mattis told reporters in Washington.

But other than using economic pressure to try to compel Pyongyang to give away its nuclear weapons — a strategy that has failed for the past decade — Trump’s administration has yet to lay out a strategy for a possible negotiated settlement. In recent weeks, the administration’s lack of direction has been all too apparent, as Trump and other top officials have vacillated between bellicose talk of possible military action and, at one point, even praise for Kim for a brief lull in missile tests.

“In the absence of such a policy roadmap, the president’s words won’t change North Korea’s behavior,” said Frank Jannuzi, an East Asia expert and president of the Washington-based Mansfield Foundation. “Nor will they bolster Chinese, Russian or allied confidence in the U.S. approach.”