North Korea on Monday fuelled speculation that it was preparing to test a long-range missile by suggesting it would go ahead with a rocket launch as part of what it called a space programme.

Pyongyang has previously tested missiles under the guise of launching a satellite and analysts said the latest comments from the North indicated the communist state was on the verge of another attention-grabbing test.

"One will come to know later what will be launched in the DPRK (North Korea)," the official Korean Central News Agency (KCNA) reported as the hardline communist state celebrated the 67th birthday of leader Kim Jong-Il.

The North is under growing pressure to scrap apparent preparations to launch its longest-range Taepodong-2 missile, which could theoretically target Alaska.

Media reports citing intelligence from satellite photos say preparations at the Musudan-ri launch site on the northeast coast are well advanced.

Hillary Clinton, who this week makes her first Asian tour as US Secretary of State, last week urged the communist state to avoid provocation and stop "unhelpful rhetoric" towards South Korea.

The North depicted its launch of a Taepodong-1 missile back in August 1998 as an attempt to put a satellite into orbit.

It test-launched its Taepodong-2, with a maximum range of 6,700 kilometres (4,190 miles), in July 2006. US officials said it failed after 40 seconds and the United Nations imposed missile-related sanctions on Pyongyang.

It also tested an atomic weapon in 2006 but experts are unsure whether Pyongyang has the capability to put a nuclear warhead on a missile.

Analysts said the North would likely portray a test as a satellite launch to avoid antagonising the new US administration excessively, even though it would also have a military purpose.

KCNA blasted rumours spread by "hostile forces" of a planned long-range missile launch.

"This is a vicious trick to put a brake on the wheel of not only the DPRK's building of military capability for self-defence but also scientific researches for peaceful purpose," it said.

"Space development is the independent right of the DPRK."

The official agency said "dishonest forces" were asserting that the North was planning a provocative act to draw attention.

"The DPRK has no need to draw anyone's attention and wants nobody to interfere or meddle in the issue of the Korean peninsula."

Analysts believe a launch would be aimed at persuading the Obama administration to make negotiations with the nuclear-armed state a priority.

Nuclear disarmament talks involving the United States and four regional powers are currently stalled, and the North is stepping up threats against South Korea's conservative government.

On Sunday its de facto head of state, Kim Yong-Nam, threatened "decisive actions" against the South if it continues to "challenge" Pyongyang.

Kim, the highest-level official to threaten the South since relations soured last year, accused Seoul of pushing relations to the brink of war by violating summit accords in 2000 and 2007.

Monday's report was the second time this month that the North has asserted its right to a space programme.

"The DPRK's policy of advancing to space for peaceful purposes is a justifiable aim that fits the global trend of the times," Rodong Sinmun newspaper said earlier, noting that Iran successfully launched a satellite.

"It's very likely for North Korea to claim that it has been a satellite launch after test-firing the missile," Baek Seung-Joo of the Korea Institute for Defence Analyses told AFP.

"It has multiple purposes for doing so -- to avoid a conflict with the new US government, to boast its advanced missile technology and also to boost internal unity by making its people take pride in the nation."

Despite Pyongayang's insistence that it has the right to space exploration, Baek said he believed the North "has no space programmes at all."

South Korea's JoongAng Ilbo newspaper said Monday the North has moved all necessary materials to its Musudan-ri base. The South's military believes a missile can be assembled faster than initially expected, it quoted an unidentified senior military official as saying.