The service's Global Strike Command said Friday in a statement that the total flight time for the B-2s was 75 hours. The aircraft made the more than 6,500-mile round trip from Whiteman Air Force Base in Missouri to a South Korean island range on Thursday.
Defense Secretary Chuck Hagel said the decision to send the B-2s for drills with South Korea was part of normal military exercises with a close ally and not intended to provoke a reaction from North Korea.
North Korea warned Seoul on Saturday that the Korean Peninsula had entered "a state of war" and threatened to shut down a border factory complex that's the last major symbol of inter-Korean cooperation.
Analysts say 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 Seoul and Washington, including a vow to launch a nuclear strike, have raised worries that a misjudgment between the sides could lead to a clash.
On Thursday, U.S. military officials revealed that two B-2 stealth bombers dropped dummy munitions on an uninhabited South Korean island as part of annual defense drills that Pyongyang sees as rehearsals for invasion. Hours later, Kim ordered his generals to put rockets on standby and threatened to strike American targets if provoked.
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 United States 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 Pyongyang's official Korean Central News Agency, referring to the North's 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.
