SEOUL, South Korea -- North Korea's leader responded Friday to America's use of nuclear-capable B-2 bombers in joint South Korean military drills with more angry rhetoric, saying his rocket forces are ready "to settle accounts with the U.S."
The threats, while not an indication of imminent war, are most likely aimed at coercing South Korea into softening its policies, to win direct talks and aid from Washington, and to strengthen young leader Kim Jong Un's credentials at home.
Kim "convened an urgent operation meeting" with his senior generals early Friday, 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.
It is the latest in the litany of apparently empty threats that North Korea has issued, including highly improbable ones to nuke the United States. Experts believe the country is years away from developing nuclear-tipped missiles that could strike the United States.
Many analysts say they've also seen no evidence that Pyongyang's missiles can hit the U.S. mainland.
Still, North Korea remains unpredictable, and its threats do raise tensions given the kind of arsenal it has: short- and mid-range missiles that can hit South Korea. Also, Seoul is only a short drive from the heavily armed border separating the Koreas.
There are fears of a localized conflict, such as a naval skirmish in disputed Yellow Sea waters. Such naval clashes have happened three times since 1999.
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. The stealth bombers' flight indicates that U.S. hostility against North Korea has "entered a reckless phase, going beyond the phase of threat and blackmail," Kim was quoted as saying.
Tens of thousands of North Koreans turned out for a 90-minute mass rally at the main square in Pyongyang in support of Kim's call to arms. Chanting "Death to the U.S. imperialists" and "Sweep away the U.S. aggressors," soldiers and students marched through Kim Il Sung Square in downtown Pyongyang.
U.S. Forces Korea said that the B-2 stealth bombers flew from a U.S. air base in Missouri and dropped dummy munitions on an uninhabited South Korean island range on Thursday before returning home. The Pentagon said this was the first time a B-2 had dropped dummy munitions over South Korea, but later added that it was unclear whether there had ever been any B-2 flights there.
The statement follows an earlier U.S. announcement that nuclear-capable B-52 bombers participated in the joint military drills.
Pyongyang also uses the U.S. nuclear arsenal as a justification for its own push for nuclear weapons. It claims that U.S. nuclear firepower is a threat to its existence and that its annual military drills with South Korea are a preparation for invasion. Washington and Seoul say the drills are routine and defensive.
U.S. Defense Secretary Chuck Hagel told reporters Thursday that the decision to send B-2 bombers to join the military drills was part of normal exercises and not intended to provoke North Korea. Hagel acknowledged, however, that North Korea's belligerent tones and actions in recent weeks have ratcheted up the danger in the region, "and we have to understand that reality."
In Washington, State Department spokeswoman Victoria Nuland said the U.S. was making sure its defenses were "appropriate and strong" as North Korea continues to test and seeks to extend the reach of its weaponry.
North Korea has already threatened nuclear strikes on Washington and Seoul in recent weeks. Earlier this month, it announced that it considers void the armistice that ended the Korean War in 1953.
But there were also signs that Pyongyang is willing to go only so far.
A North Korean industrial plant operated with South Korean know-how was running normally Friday, despite the North's shutdown two days earlier of communication lines ordinarily used to move workers and goods across the border. At least for the moment, Pyongyang was choosing the factory's infusion of hard currency over yet another provocation.
Pyongyang would have gone beyond words, possibly damaging its own weak finances, if it had blocked South Koreans from getting in and out of the Kaesong industrial plant, which produced $470 million worth of goods last year.
The Kaesong plant, just across the heavily fortified Demilitarized Zone that separates the Koreas, normally relies on a military hotline for the governments to coordinate the movement of goods and South Korean workers.
Without the hotline, the governments, which lack diplomatic relations, used middlemen. North Korea verbally approved the crossing Thursday and Friday of hundreds of South Koreans by telling South Koreans at a management office at the Kaesong factory. Those South Koreans then called officials in South Korea.
Both governments prohibit direct contact with citizens on the other side, but Kaesong has separate telephone lines that allow South Korean managers there to communicate with people in South Korea.
Factory managers at Kaesong reached by The Associated Press by telephone at the factory said the overall mood there is normal.
"Tension rises almost every year when it's time for the U.S.-South Korean drills to take place, but as soon as those drills end, things quickly return to normal," Sung Hyun-sang said Thursday in Seoul, a day after returning from Kaesong. He is president of Mansun Corporation, an apparel manufacturer that employs 1,400 North Korean workers and regularly stations 12 South Koreans at Kaesong.
"I think and hope that this time won't be different," Sung said.
Technically, the divided Korean Peninsula remains in a state of war. North Korea last shut down communications at Kaesong four years ago, and that time some workers were temporarily stranded.
South Korea urged the North to quickly restore the hotline, and the U.S. State Department said the shutdown was unconstructive.
-- AP writers Hyung-jin Kim and Sam Kim contributed to this report.