North Korea threatened to "retaliate against the U.S. with tremendous muscle" if it didn't cancel multinational military exercises scheduled to begin Monday.

"The further Ulchi Freedom Guardian joint military exercises are intensified, the strongest military counteraction the (Democratic People's Republic of Korea) will take to cope with them," a spokesman for North Korea's National Defense Commission (NDC) said Saturday.

While threatening military action is nothing new for the regime (Kim Jong Un told his troops they should be ready to fight a "sacred war" in the days leading up to the exercises in 2012, for example), the rhetoric coming out of Pyongang seems particularly ratcheted-up this time around.

"The army and people of the DPRK are no longer what they used to be in the past when they had to counter the U.S. nukes with rifles," the NDC spokesman continued, saying North Korea "is the invincible power equipped with both [the] latest offensive and defensive means unknown to the world..."

A state television report repeated the claim that this isn't the same old, ill-equipped North Korea that never could stand up to the United States in the past. In fact, this year, they are threatening to attack the U.S. on its own soil.

"If [the] United States wants their mainland to be safe," said a newswoman for the state TV station, KCNA, "then the Ulchi Freedom Guardian should stop immediately."