BEDMINSTER, N.J.  — President Donald Trump issued a new threat to North Korea on Thursday, demanding that Kim Jong Un’s government “get their act together” or face extraordinary trouble. He said his previous “fire and fury” warning to Pyongyang might have been too mild.

“Maybe that statement wasn’t tough enough,” Trump said in the latest round of an escalating exchange of threats between the two nuclear-armed nations.

Speaking to reporters in New Jersey, Trump said North Korea has been “getting away with a tragedy that can’t be allowed.” Still, he declined to say whether the U.S. is considering a pre-emptive military strike, arguing that his administration never discusses such deliberations publicly.

Trump spoke after North Korea intensified its own rhetoric by announcing a detailed plan to launch a salvo of ballistic missiles toward the U.S. Pacific territory of Guam, a major military hub and home to U.S. bombers. That announcement had been a response to Trump’s threat that the North would face “fire and fury like the world has never seen” if it threatened the U.S. again.

On Thursday, Trump said it is time somebody stood up to the pariah nation.

“North Korea better get their act together or they are going to be in trouble like few nations have ever been in trouble,” Trump said, flanked by Vice President Mike Pence. “It may very well be tougher than I said.”

Trump spoke after meeting with national security advisers at the golf resort where he’s vacationing. He said the U.S. “of course” would always consider negotiations with North Korea, but added that talks with the North have failed for the last 25 years. He said that China, the North’s biggest trading partner, needs to do more to apply pressure — and predicted that it will.

The threatened attack near Guam, if carried out, would be the North’s most provocative missile launch to date. The North said it is finalizing a plan to fire four of its Hwasong-12 missiles over Japan and into waters around the tiny island, which hosts 7,000 U.S. military personnel on two main bases and has a population of 160,000.