"I don't believe they will carry through on these threats," Bill Richardson, former New Mexico governor and former emissary to North Korea, told The New York Times.
"It does mean a longer or sustained period of estrangement and negativity and lack of a diplomatic dialogue," he said. "I think to show their defiance they may take some military steps, undefined military steps. I don't know what they'll do."
North Korea, an impoverished, isolated Communist country, has stepped up its threatening statements because of United Nations Security Council sanctions over its missile and nuclear tests and developments such as the joint U.S.-South Korean military exercises, which it has said are a prelude to war. It sees the tightening U.N. Security Council sanctions, the latest of which were unanimously approved Thursday for its Feb. 12 nuclear test, as an "act of war."
It has also scrapped the 1953 armistice that ended the Korean War and threatened to turn Washington and Seoul into "a sea in flames" with "lighter and smaller nukes."
"Now that the U.S. is set to light a fuse for a nuclear war, the revolutionary armed forces of the DPRK [North Korea] will exercise the right to a pre-emptive nuclear attack to destroy the strongholds of the aggressors and to defend the supreme interests of the country," a North Korean Foreign Ministry spokesman was quoted as saying Thursday.
Some analysts told the Times the latest threat from the North appeared meant as much for its own people as to force Washington to engage it with concessions.
They also said they don't believe North Korea would attack the United States as that would be suicidal for its regime. But officials in South Korea told the Times they fear the North might launch an armed skirmish to test the military resolve of Park Geun-hye, South Korea's new and first female president.
Earlier this week, a South Korean military general, in a warning against any such North Korean provocation, went so far as to indicate his country would not spare even the top North Korean military elite headed by the country's leader, Kim Jong Un.
Analysts speaking to CNN said North Korea, despite its strong threats, is nowhere near having the technology to mount a nuclear warhead on a missile and aim it accurately at a target.
Some analysts told CNN the North is likely prefer to gain traction through threats and the buildup of its military deterrent.
But the new threats come with growing concern over the North's determined efforts to advance its nuclear and missile technology as seen by its long-range rocket launch in December and the February underground atomic blast.
The North's latest threat Thursday "may suggest that Pyongyang feels even more boxed in than usual," Michael Mazza of the American Enterprise Institute told CNN.
Although a nuclear attack is not an immediate palpable threat, Michael Auslin, also the AEI, told CNN the surge in the provocative rhetoric is particularly dangerous.
"South Korea's new president [Park Geun Hye] can't be seen to back down in the face of the North's threats, while Kim Jong Un may feel that his successful missile and nuclear tests give him the ability to keep pressuring Seoul. The two may wind up talking themselves into conflict," he said.
Other analysts, speaking to CNN, said they doubt whether the new sanctions will make much difference as previous sanctions have not stopped the North from conducting its tests.
"As long as China allows North Korea to operate, as long as China provides food, energy assistance and investment, the sanctions really don't matter," Doug Bandow at Cato Institute told CNN.
But Mark Fitzpatrick, director of non-proliferation and disarmament at the International Institute for Strategic Studies in Britain, said recently Kim Jong Un is now paying the price for going ahead with a nuclear test despite Chinese warnings against it during the political transition in China.
He said future Chinese grain sales to North Korea may indicate China's commitment to putting meaningful pressure on North Korea.