SEOUL, South Korea -- North Korean leader Kim Jong Un warned Friday that his rocket forces were ready "to settle accounts with the U.S.," unleashing a new round of bellicose rhetoric after U.S. nuclear-capable B-2 bombers dropped dummy munitions in joint military drills with South Korea.

Experts say Kim's warning and the litany of threats that have preceded are likely meant to coerce South Korea into softening its policies, win direct talks and aid from Washington, and strengthen the young leader's image at home.

But Saturday the North declared it has entered a state of war with the South. "Every issue raised between the North and South will be dealt in a wartime manner," the state-run Korean Central News Agency said, citing what it called a special statement.

North Korea's threat isn't new, South Korea's Unification Ministry said in a statement Saturday.

But the escalating tensions following UN sanctions over Pyongyang's Feb. 12 nuclear test have raised worries of a misjudgment leading to a clash.

The White House said the threats to fire rockets on the United States only deepen the country's isolation from the world.

White House spokesman Josh Earnest said the United States has the capability and willingness to defend its interests in the region. He called on North Korea to put its people first by ending its "bellicose rhetoric," abandoning its nuclear program and living up to its international obligations.

Kim "convened an urgent operation meeting" of senior generals just after midnight, signed a rocket preparation plan and ordered his forces on standby to strike the U.S. mainland, South Korea, Guam and Hawaii, state media reported.

Kim said "the time has come to settle accounts with the U.S. imperialists in view of the prevailing situation," according to a report by the North's official Korean Central News Agency.

Later Friday at the main square in Pyongyang, tens of thousands of North Koreans turned out for a 90-minute mass rally in support of Kim's call to arms. Men and women, many of them in olive drab uniforms, stood in arrow-straight lines, fists raised as they chanted, "Death to the U.S. imperialists." Placards in the plaza bore harsh words for South Korea as well, including, "Let's rip the puppet traitors to death!"

advertisement | advertise on newsday

Small North Korean warships, including patrol boats, conducted drills off both coasts of North Korea near the border with South Korea on Thursday, South Korean Defense Ministry spokesman Kim Min-Seok said in a briefing Friday. He didn't provide more details.

With Bloomberg News