The statement from the North Korean foreign ministry is the first to lay out Pyongyang's nuclear stance since the last round of six-party talks on disarmament held in Beijing December.
The negotiations involve envoys from North and South Korea, China, Japan, Russia and the US.
Talks 'under review'
"We would never show our nuclear weapons first - even in 100 years - unless the US hostile policy and nuclear threat to North Korea are terminated."
North Korean foreign ministry statement.
In her testimony to the US senate foreign relations committee, Clinton said the six-party talks could act as a basis for bilateral openings between North Korea and the US, which could ultimately be a way to achieve the overriding US goal of ending North Korea's nuclear weapons programme.
The outgoing Bush administration has rejected North Korea calls for bilateral talks with the US, saying any discussions on the North's nuclear programme must take place under the umbrella of the six-party process.
But Barack Obama, the US president-elect, has indicated he will take a different tack with North Korea, suggesting during last year's election campaign that he would be prepared to hold one-to-one talks with North Korean leaders if it would lead to a breakthrough.
Speaking to members of the US senate foreign relations committee Clinton said the framework of the frequently-delayed six-party talks was "under review", with officials looking in detail at the achievements made so far.
But she said the six-nation talks remained a useful way to exert pressure on the North to abandon its nuclear development.
"We will embark upon a very aggressive effort to try to determine the best way forward to achieve our objectives with them," she said.
In 2005, the North agreed to abandon its nuclear weapons programme in return for aid and other concessions.
However, the process has been stalled for months because of a standoff with Washington over how to verify Pyongyang's past nuclear activities.
North Korea said verification must take place at the last stage of the disarmament process - not the second of three phases as the US wants.
|Obama has said he would be willing to meet North Korean leader Kim Jong-il [AFP]
The North has also demanded that Washington must at the same time reveal what it says is a US nuclear arsenal held South Korea.
In its statement carried by the state-run Korean Central News Agency, the foreign ministry reiterated its commitment to a nuclear-free Korean peninsula.
"It is necessary to simultaneously verify the whole Korean peninsula," the statement said.
It added: "We would never show our nuclear weapons first - even in 100 years - unless the US hostile policy and nuclear threat to North Korea are terminated."
Seoul and Washington deny having a secret atomic arsenal.
"We don't have nuclear weapons,'' Moon Tae-young, the South Korean foreign ministry spokesman, told the Associated Press on Tuesday.
The US military does however have some 28,000 troops based in the South and holds regular war games with the South Korean military - exercises the North claims as proof of US aggression.