Trump says "only one thing will work" with North Korea

"Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid," Trump said in a tweet. "...Hasn't worked, agreements violated before the ink was dry, making fools of U.S. negotiators. Sorry, but only one thing will work!"

The president has previously said the United States would "totally destroy" North Korea if necessary to protect itself and its allies from Pyongyang's nuclear threats.

Earlier this week, during a meeting with top U.S. military leaders and their spouses, Trump told reporters it was the "calm before the storm." Asked for clarification then on what he meant, Trump said: "You'll find out."

Speaking to reporters on Saturday ahead of a trip to North Carolina, Trump said he had nothing more to clarify.

Trump said on Saturday he had a good relationship with Secretary of State Rex Tillerson but that Tillerson could be tougher.

Trump, who made the comment to reporters at the White House, did not elaborate.

NBC reported this week that in a session with Trump's national security team and Cabinet officials at the Pentagon, Tillerson had openly criticized the president and referred to him as a "moron."

Tillerson on Wednesday (October 4) said he had never considered resigning and was committed to Trump's agenda, but failed to address whether he had referred to the president as a "moron," as NBC reported.