Overnight,

the U.S. flexing its muscle and sending stealth bombers into the backyard of the mysterious nation.

As tonight,

the North Korean news agency says they are “burning with hatred”

over this latest move. And ABC News Chief Global Affairs Correspondent Martha Raddatz tells us the story.

If North Korea had any doubt that the U.S. would defend its ally South Korea,

this rare show of force should end it.The two massive B2s sought 6500 miles from Missouri to drop dummy weapons on a bombing range west of South Korea and less than 50 miles from the North Korean border, and then flew back to the U.S.

It was the first time the U.S. military has confirmed the B2 practice mission but the message was clear.

The B2 was capable of dropping 16 nuclear bombss each on a different target.

It can fire under any weather conditions,

penetrating sophisticated air defences with its rader-evading stealth scan.

“We will unequivocally defend and we are unequivocally commited to that alliance with South Korea.

And we will be prepared if we have to be prepared to deal with any eventuality there.”

Since February when the U.S. and South Korea began gearing up for military exercises,

North Korea steadily escalated its threats. A page from its playbook,

only this time those threats have been harder,

including nuclear strikes which they are not yet capable of.

The U.S. says the stealth bombers were not meant to ratchet up the tension with North Korea but that is exactly what has happened.