BRIDGEWATER, N.J. — President Donald Trump starkly warned North Korea to stop making nuclear threats Tuesday in the kind of bellicose rhetoric usually associated with Pyongyang, twice declaring it will be “met with fire and fury like the world has never seen.”

The president’s threat of annihilation raised fresh fears of a confrontation with North Korea, which successfully tested an intercontinental ballistic missile last month for the first time and which has vowed to defend itself with nuclear weapons if necessary.

A statement from North Korea’s military later Tuesday did not mention Trump’s threat but warned that Pyongyang was “carefully examining” a plan to attack Guam, the U.S. territory in the western Pacific, with “enveloping fire” from medium and long-range missiles.

U.S. bombers based on Guam have flown over the Korean Peninsula in recent weeks in shows of force in response to North Korean missile tests. Guam hosts thousands of U.S. service members at Andersen Air Force Base and U.S. Naval Base Guam.

Trump’s heated rhetoric, which apparently caught the Pentagon by surprise, followed a new classified intelligence assessment indicating that North Korea has developed a warhead that could fit atop an intercontinental ballistic missile, or ICBM.

The intelligence report hardens previous classified assessments that date to 2013 and reflects growing confidence by the U.S. intelligence community that Pyongyang has achieved a nuclear weapons milestone after years of uncertainty.

U.S. officials caution that North Korea still has not produced a nuclear warhead capable of surviving the intense heat, vibration and pressure of an ICBM’s fiery re-entry into the atmosphere, but that step appears increasingly likely.

The North Korean military statement urged the Trump administration to “immediately stop its reckless military provocation” and warned “it is a daydream for the U.S. to think that its mainland is … invulnerable.”

Trump spoke from the clubhouse of his golf resort in Bedminster, N.J., where he is on what the White House calls a 17-day working vacation.

He adopted the inflammatory language North Korean leaders have used for years to threaten the United States.

“North Korea best not make any more threats to the United States,” Trump told reporters, his arms folded across his chest, immediately overshadowing a meeting he had called to discuss America’s opioid epidemic. “They will be met with fire and fury like the world has never seen.”

He added that North Korean leader Kim Jong Un “has been very threatening beyond a normal state. And as I have said, they will be met with fire, fury, and frankly power, the likes of which this world has never seen before.”

For years, Pyongyang’s official news service has spewed out threats to turn Seoul into a “sea of fire” or engulf the United States in “thermonuclear war.” Those threats are often received with shrugs.

But with Trump responding with his own fiery threat, experts fear he raises the risk of a miscalculation that could tempt North Korea to try to up the ante.

“To start throwing out this hyperbole about death and destruction, I don’t know how that’s helpful,” said Carl Baker, a retired Air Force officer who was stationed in South Korea, now with the Pacific Forum CSIS in Honolulu.

Until Tuesday, the Trump administration had used traditional diplomatic channels to deal with the crisis, winning a unanimous United Nations Security Council vote to impose tough sanctions on North Korea in response to its latest ballistic missile tests.

And at a regional security conference in the Philippines on Sunday, Secretary of State Rex Tillerson offered to resume negotiations with Pyongyang if it would stop ballistic missile tests as a show of good faith.

Analysts fear that Trump’s comments added a dangerous new level of brinksmanship to the nuclear standoff between an untested U.S. president and a North Korean ruler who is believed to be in his early 30s.

The latest crisis began when North Korea tested its first two intercontinental ballistic missiles last month, with the second judged powerful enough to conceivably reach California and beyond.

A Defense Intelligence Agency report dated that same day, July 28, also rang alarms.

It assessed that Pyongyang is now capable of producing so-called miniaturized nuclear warheads to fit atop an ICBM, a critical step in the nation’s decade-long march to develop a nuclear strike force, U.S. officials said.

Sen. John McCain, R-Ariz., said in a radio interview in Arizona that “I take exception to the president’s comments because you’ve got to be sure you can do what you say you can do. ...

“That kind of rhetoric, I’m not sure how it helps.”

Los Angeles Times staff writer Ralph Vartabedian contributed from Los Angeles and Barbara Demick from New York.

william.hennigan@latimes.com