North Korea pledged Tuesday to develop more nuclear weapons as its existing arsenal has helped raise the country's strategic leverage in dealing with external relations, the North's state media said.

North Korea plans to actively pursue diplomatic policy commensurate with its enhanced global status which has been earned thanks to its nuclear weapons program, according to Rodong Sinmun, the North's main newspaper.

The country has conducted four nuclear tests since 2006 with outside observers believing the North has a small stockpile of nuclear weapons.

"We will produce more modern and diverse nuclear weapons," the newspaper said. "The weapons are not aimed at posing a threat to peace. We will not use nuclear weapons if aggressors do not attack us with nukes," it said.

North Korean leader Kim Jong-un has referred to his country as a "responsible" nuclear state at the congress of the ruling Workers' Party of Korea held in early May.

Kim made it clear that he will "permanently" defend the pursuit of his signature policy of developing nuclear weapons in tandem with boosting the country's moribund economy, commonly known as the "byeongjin" policy.

The North claims that it has succeeded in making a nuclear warhead small enough to fit on a ballistic missile, but Seoul and Washington said that Pyongyang's miniaturization technology has not been fully achieved.

The newspaper report came as North Korea is engaged in a flurry of diplomacy apparently to drive a wedge in united fronts for imposing sanctions over the communist country's nuclear test and long-range rocket launch early this year.

Ri Su-yong, a vice chairman of the ruling Workers' Party, made a rare visit to China last week in an apparent bid to improve strained ties with Beijing following Pyongyang's nuclear tests.

North Korea's ceremonial head of state, Kim Yong-nam, also visited Equatorial Guinea last month to attend the inauguration ceremony of the president of the African country. (Yonhap)