North Korea should be 'very very nervous': Donald Trump

"The people of our country are safe. Our allies are safe. 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 told reporters in New Jersey, where he was meeting with his national security team.

Far from toning down his words after saying on Tuesday that any threats by Pyongyang would be "met with fire and fury like the world has never seen," Trump said those remarks may have not gone far enough. "Maybe it wasn't tough enough. 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 and for the people of other countries," Trump added.

Asked if he would consider a pre-emptive strike against North Korea to deny it the ability to launch a nuclear attack against the United States, Trump said, "We'll see what happens." "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 should be very, very nervous. I'll tell you what. And they should be very nervous. Because things will happen to them like they never thought possible," Trump added.

North Korea's army will complete the plans in mid-August to fire four intermediate-range missiles over Japan to land near Guam, when they will be ready for leader Kim Jong Un's order, state-run KCNA news agency said, citing General Kim Rak Gyom, commander of the Strategic Force of the Korean People's Army. The plans called for the missiles to land in the sea 30-40 km (18-25 miles) from Guam.