North Korea's new constitution proclaims its status as a nuclear-armed nation, complicating international efforts to persuade Pyongyang to abandon atomic weapons, analysts said Thursday.

An official website seen late Wednesday released the text of the constitution following its revision during a parliamentary session on April 13.

"National Defence Commission chairman Kim Jong-Il turned our fatherland into an invincible state of political ideology, a nuclear-armed state and an indomitable military power, paving the ground for the construction of a strong and prosperous nation," says part of the preamble.

The text was carried by the "Naenara" (My Nation) website.

The previous constitution, last revised on April 9, 2010, did not carry the term "nuclear-armed state".

Following Kim Jong-Il's death last December, the country revised the charter to consecrate achievements of the late leader, who was succeeded by his son Kim Jong-Un.

The North has been developing nuclear weapons for decades. Its official position has been that it needs them for self-defence against a US nuclear threat, but that it is willing in principle to scrap the atomic weaponry.

Under a September 2005 deal reached during six-nation negotiations, Pyongyang agreed to dismantle its nuclear programmes in return for economic and diplomatic benefits and security guarantees.

But six-party talks on implementing the deal have been stalled since December 2008. The North has staged two nuclear tests, in 2006 and 2009.

"This makes it clear that the North has little intention of giving up nuclear programmes under any circumstances," Cheon Sung-Whun of the state Korea Institute for National Unification told AFP.

"If there is a demand at the negotiation table to give up nuclear weapons, the North Koreans would say it would be a breach of the constitution," he said.

North Korea has long been in confrontation with the United States and its allies over its nuclear and missile programmes.

Its April 13 long-range rocket launch, purportedly a peaceful mission to put a satellite into orbit, further dimmed prospects for a diplomatic settlement.

The revised constitution "is certainly bad news for participants in the six-party talks", said Professor Kim Keun-Sik at Kyungnam University in Changwon.

"It will make it harder to persuade the North to give up nuclear weapons through diplomacy."

But Kim cautioned against reading too much into what was intended as part of a eulogy for Kim Jong-Il.

"The North has been touting its nuclear status as one of the key achievements accredited to the late leader and the new constitution factors this in," he said.

"This can hardly be interpreted as a message that it will stick to its nuclear weapons no matter what."

Kim also said the North's constitution can easily be amended once its ruler decides to do so, noting it was revised twice in as many years.

The six-party talks which began in 2003 are chaired by China and also include the two Koreas, the United States, Russia and Japan.