A day earlier, the same official North Korean news agency reported its leader Kim Jong Un had approved a plan to prepare standby rockets to hit U.S. targets in the Pacific, including in Hawaii, Guam, and South Korea.
Behind North Korea's heated words about missile strikes, one analyst said, there might not be much mettle.
"Unless there has been a miraculous turnaround among North Korea's strategic forces, there is little to no chance that it could successfully land a missile on Guam, Hawaii or anywhere else outside the Korean Peninsula that U.S. forces may be stationed," James Hardy, Asia-Pacific editor of IHS Jane's Defense Weekly, wrote in an opinion column published Thursday on CNN.com.
U.S. official: We're 'committed ... to peace'
U.S. defense officials said Friday that the North's bantering is destructive.
"This is troubling rhetoric that disrupts the prospects for peace on the Peninsula," the senior official said.
Some observers have suggested that Washington is adding to tensions in the region by drawing attention to its displays of military strength on North Korea's doorstep, such as the flights by the B-2 stealth bombers.
Defense Secretary Chuck Hagel argued against that assertion Thursday.
"We, the United States and South Korea, have not been involved in provocating anything," he said. "We, over the years, have been engaged with South Korea on joint exercises. The B-2 flight was part of that."
Washington and its allies "are committed to a pathway to peace," Hagel said. "And the North Koreans seem to be headed in a different direction here."
Pyongyang's allies irked
The tense situation has irritated North Korea's traditional allies, China and Russia, drawing regular calls for restraint on all sides in recent weeks. Saturday, the Kremlin repeated this admonition.
"Moscow expects all parties to exercise as much responsibility and restraint as possible in light of North Korea's latest statements," the Russian foreign ministry said according to Russian state broadcaster Russia Today.
China, which has expressed frustration over Pyongyang's latest nuclear test, also called for calm.
"We hope relevant parties can work together to turn around the tense situation in the region," Foreign Ministry spokesman Hong Lei said Friday, describing peace and stability on the Korean Peninsula as "a joint responsibility."
Sweden's Foreign Minister Carl Bildt noted Saturday that "Beijing likely to try to calm things down," he said on his Twitter account.
"But the Pyongyang regime is the most militarised, the most authoritarian and the most closed in the world," Bildt tweeted.
Tensions have been rising for months
Tensions escalated on the Korean Peninsula after the North carried out a long-range rocket launch in December and an underground nuclear test last month, prompting the U.N. Security Council to step up sanctions on the secretive government.
Pyongyang has expressed fury about the sanctions and the annual U.S.-South Korean military exercises, due to continue until the end of April.
The deteriorating relations have killed hopes of reviving multilateral talks over North Korea's nuclear program for the foreseeable future. Indeed, Pyongyang has declared that the subject is no longer up for discussion.