President Donald Trump doubled down Thursday on warnings to North Korea, saying comments he made earlier in the week implying the U.S. would hit the country with “fire and fury” could have been harsher.

“Maybe it wasn’t tough enough,” Trump said from his golf club in New Jersey. “They’ve been doing this to our country for a long time, for many years, and it’s about time that somebody stuck up for the people of this country.”

When asked what kind of rhetoric would be tougher than “fire and fury,” the president responded: “You’ll see. You’ll see.”

Asked to provide assurance to Americans who are anxious about the possibility of nuclear warfare, Trump said people should be “comfortable” but threw in another warning to Pyongyang.

“If North Korea does anything in terms of even thinking about attack of anybody that we love or we represent or our allies or us, they can be very, very nervous,” he said. “They should be very nervous because things will happen to them like they never thought possible, OK?”

“He’s been pushing the world around for a long time,” the president added, referring to the North Korean leader Kim Jong Un. 

Trump declined to discuss the possibility of a pre-emptive attack.

“We don’t talk about that. I never do.” he said. “What they’ve been doing, what they’ve been getting away with, is a tragedy and it can’t be allowed.”

Trump was speaking to pool reporters ahead of a national security briefing at his golf course in Bedminster, New Jersey, that also included national security adviser H.R. McMaster and White House Chief of Staff John F. Kelly. The president said his statements were “100 percent” backed up by the military.

“The people of our country are safe. Our allies are safe,” Trump said. “And I will tell you this, North Korea better get their act together or they’re going to be in trouble like few nations ever have been in trouble in this world.”

Trump warned Pyongyang earlier this week that the United States would unleash its nuclear arsenal if the isolated nation repeated threats that it would strike American targets.

“It is now far stronger and more powerful than ever before,” the president tweeted Wednesday about the U.S. nuclear arsenal.

Reports emerged this week that North Korea has developed a nuclear warhead that can ride atop its suddenly effective long-range missiles, which, some analysts say, could reach Chicago.

Meanwhile, Secretary of State Rex Tillerson has taken a more subdued approach to the rhetorical escalation with North Korea. After landing in Guam on Wednesday, he said he saw no imminent threat of war.

The messages amounted to a good cop, bad cop routine, which previous U.S. presidents and Cabinet officials have employed both domestically and abroad.

“I think the president just wanted to be clear to the North Korean regime that the U.S. has the unquestionable ability to defend itself, will defend itself and its allies,” Tillerson said during a planned refueling stop on the island territory. “And I think it was important that he deliver that message to avoid any miscalculation on their part.”

When asked if his secretary of state’s comments delivered confusing signals, Trump said there “were no mixed messages.”

Contact Rahman at remarahman@cqrollcall.com or follow her on Twitter at @remawriter