Only "one thing" will work to resolve the North Korea nuclear crisis, Donald Trump has warned.
Mr Trump made the ominous prediction days after Rex Tillerson said the administration was in "direct" talks with Pyongyang.
It comes after the stand-off between the two countries over the regime's bid to make nuclear weapons reached its deepest levels in years.
The US president and North Korean leader Kim Jong-un have exchanged a number of insults and threats in recent months.
In a series of tweets on Saturday, Mr Trump said North Korea had been making "fools" out of US negotiators for 25 years.
He warned that "only one thing" would work to resolve the crisis.
Mr Trump said: "Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid.
"[It] Hasn't worked, agreements violated before the ink was dry, making fools of US negotiators.
"Sorry, but only one thing will work."
Last week, Secretary of State Mr Tillerson said the US was "probing" the possibility of formal talks with the hermit nation in a bid to rein in its nuclear ambitions.
But Mr Trump claimed his colleague was "wasting his time".
"I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man," Mr Trump said.
The US president has previously warned he would be prepared to "totally destroy" North Korea if the US was forced to defend itself.
Both Kim and Mr Trump have claimed the other are on "suicide" missions.
Over the past year, North Korea has test fired ballistic missiles and nuclear bombs at an unprecedented rate - suggesting the country is nearing its goal of becoming a fully-fledged nuclear nation.
America has warned it cannot accept that proposition.