WASHINGTON (Yonhap) -- North Korea will likely develop intercontinental ballistic missiles capable of delivering nuclear warheads within the coming decade, the chief U.S. military officer said Thursday.

   "There's little doubt in my mind, unless North Korea is deterred, that sometime in the next, I'm not sure but, five to 10 years, the provocations ... will continue at a much higher threat level, which could include a nuclear-capable ICBM," Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, said in an interview with Financial Times, according to a transcript released by the Pentagon. "That's what I believe we're looking at. I can't be precise about the time and say it's exactly here but clearly there is evolution going on there where the threat becomes much more serious."

   Mullen's statement is in tune with Defense Secretary Robert Gates, who said earlier this month that North Korea's missiles and nuclear weapons will pose a threat to the U.S. within five years.

Gates also urged North Korea to impose a moratorium on nuclear and missile testing to help revive the six-party nuclear talks.

   A six-party deal signed in 2005 by the two Koreas, the U.S., China, Japan and Russia calls for the North's nuclear dismantlement in return for massive economic aid and diplomatic and political benefits. The talks, however, have been deadlocked for more than two years over the North's nuclear and missile tests and other provocations.

   North Korea also revealed in November a uranium enrichment plant that could serve as a second way of building nuclear bombs in addition to its existing plutonium program, despite Pyongyang's claims it is producing fuel for power generation.

   "I think we all agree it's a more dangerous place now than it was a few months ago and that the provocations -- and this is all tied to the succession thing and Kim Jong Il, who's been a pretty unpredictable guy for a long time -- the worry tied to this revelation on the nuke, the uranium enrichment piece, all of that, that it's now more dangerous than it was a few months ago," Mullen said.

   The North's recent provocations, including the artillery attack on a South Korean border island and the sinking of a warship, are widely believed to be linked to the ailing North Korean leader Kim's plans to transfer power to his third and youngest son, Jong-un, in the unprecedented third generation hereditary power transition.

   The 28-year-old heir apparent, who like his father lacks a proper military background, is believed to be trying to rally support from the military, the only power base in the impoverished, but nuclear-armed communist state.

   North Korea detonated nuclear devices in 2006 and 2009, and conducted long-range missile tests three times - in 1998, 2006 and

2009 - which were seen as a partial success.

   Pyongyang is believed to have at least several nuclear weapons, with some experts saying it could have already developed nuclear warheads small enough to be mounted on ballistic missiles with the help of China or Pakistan.