"We've seen reports of a new and unconstructive statement from North Korea,” said Caitlin Hayden, a spokeswoman for the White House National Security Council. “We take these threats seriously and remain in close contact with our South Korean allies. But, we would also note that North Korea has a long history of bellicose rhetoric and threats, and today's announcement follows that familiar pattern."
North Korea made the comments after two U.S. B-2 stealth bombers dropped dummy munitions earlier this week on an uninhabited South Korean island, part of annual defense drills that North Korean sees as rehearsals for invasion.
The country’s young leader, Kim Jong Un, ordered his generals to put rockets on standby and threatened to strike American targets if provoked.
On Saturday, he also threatened to shut down a border factory complex that is the last major symbol of inter-Korean cooperation.
The threats are seen as part of an effort to provoke the new government in Seoul to change its policies toward Pyongyang and to win diplomatic talks with Washington that could get it more aid.
The moves also are seen as ways to build domestic unity as Kim strengthens his military credentials.
Military analysts have said a full-scale conflict is extremely unlikely, noting that the Korean Peninsula has remained in a technical state of war for 60 years. But the North's continued threats toward South Korea and the United States, including a vow to launch a nuclear strike, have raised worries that a misjudgment between the sides could lead to a clash.
In addition to the military exercise, Defense Secretary Chuck Hagel also announced, the U.S. will fortify its defenses against a potential North Korean missile attack by adding more than a dozen missile interceptors to the 26 already in place at Fort Greely, Alaska.
North Korea said in a statement Saturday that it would deal with South Korea according to "wartime regulations" and would retaliate against any provocations by the U.S. and South Korea without notice.
"Now that the revolutionary armed forces of the DPRK have entered into an actual military action, the inter-Korean relations have naturally entered the state of war," said the statement, which was carried by the official North Korean news agency and referred to the country by its official name, the Democratic People's Republic of Korea.
Provocations "will not be limited to a local war, but develop into an all-out war, a nuclear war," the statement said.
The White House has stressed the U.S. government's capability and willingness to defend itself and its allies and interests in the region, if necessary.
“We remain fully prepared and capable of defending and protecting the United States and our allies," Hayden said.
On Friday, Hagel condemned North Korea's response to the U.S. military exercise, including putting artillery forces on alert. He calling the country’s actions "provocative" and said it had struck a “belligerent tone.”
On Thursday, White House Deputy Press Secretary Josh Earnest said North Korea is engaging in "bellicose rhetoric" and that the U.S. commitment to protect its interests and allies in the region “is something that should be evident."
The Associated Press contributed to this report.
Published March 30, 2013FoxNews.com