WASHINGTON (NYTIMES) - It was only a few hours after his secretary of state cracked open the door on Thursday (April 27) to negotiating with the North Koreans that President Donald Trump stepped in with exactly the kind of martial-sounding threats against the country that the White House, until now, had carefully avoided.

"There is a chance that we could end up having a major, major conflict with North Korea," he said to Reuters during a round of his 100-days-in-office commemorations. "Absolutely."

Viewed in the most charitable light, Trump was, in his own non-diplomatic way, building pressure to force the North to halt its nuclear and missile tests, the first step toward resuming the kind of negotiations that Secretary of State Rex Tillerson has begun to talk about.

If so, the North Koreans did not pick up on the hint: A few hours after Tillerson told the United Nations Security Council it must vigorously enforce sanctions against the North, Pyongyang launched another missile.

Like many before it, the launch failed, leaving open the question of whether an American sabotage program or other causes were responsible.

Another possibility is that Trump was engaging in a bit of the "madman theory" that he and many of his aides reportedly admire about President Richard M. Nixon, who tried to convince Ho Chi Minh, the wily North Vietnamese leader, that he might be crazy enough to drop "the bomb" if they could not find a way to end the Vietnam War.

But the most likely explanation is that Trump, who until now has largely avoided taking the bait that the North Korean propaganda machine churns out with its own warnings of imminent war, simply reverted to an old habit: sounding as tough as the other guy.

The problem is that it clashes with the message his administration has been sending out in recent days that no pre-emptive strikes are planned and that there is plenty of time and space for diplomacy. Trump's aides talk instead of an "integrated strategy" of escalating military and economic pressure to force diplomatic engagement.

Admiral Harry Harris, who heads the US Pacific Command, told Congress this week that the objective is to "bring Kim Jong Un to his senses, not to his knees," a reference to the insecure if absolute leader of North Korea.

That also seemed to be Tillerson's message. In an interview with NPR, he tried to sound reassuring, saying: "We do not seek a collapse of the regime. We do not seek an accelerated reunification of the peninsula. We seek a denuclearised Korean Peninsula."

But he left unclear what conditions North Korea would have to fulfill before Washington engaged in any direct talks, saying the North first "must take concrete steps to reduce the threat that its illegal weapons program poses to the United States and its allies."

No one seems clear on what those "concrete steps" are. At one point in Seoul last month, Tillerson suggested the North must first completely disarm, though lately he has hedged that wording.

But whatever the preconditions, Trump missed an opportunity to reinforce that effort to reassure the North Koreans that the United States is not looking to topple their leader. Instead, his message could be taken as the opposite.

Trump's negotiating strategy has often involved the taking of an extreme position, hoping that the other actor in a test of wills will be thrown off enough to move in his direction. That is one thing when it means threatening to pull out of NAFTA, the gambit Trump floated, then retreated from, this week.

But it can be a far riskier bet when exchanging signals with Kim, who has survived - like his father and grandfather before him - by employing a similar playbook of extreme rhetoric, often followed by acts of violence.

The fear is that small acts and mutual threats of war can lead to miscalculation. Only hours before Trump spoke, the North released a propaganda video showing the White House shattering apart in what looked like a nuclear blast. No one takes those videos seriously, but they indicate a state of mind in which every action has to have a reaction.

"That's what I worry about the most," Democratic Senator Edward J. Markey said recently. "Rapid escalation."