North Korea's push to develop nuclear arms is part of its struggle to establish deterrence against the United States rather than a scheme to launch a preemptive strike on the continental U.S., a prominent American expert said Monday.

David Albright, head of the U.S-based non-governmental Institute for Science and International Security, said that the communist regime has been utilizing the process of developing atomic bombs to ensure its deterrence.

He made the remarks during his speech on the status of the world's nuclear materials at George Washington University in Washington D.C.

Touching on the North's increasingly menacing rhetoric against the South and the U.S., the scholar pointed out that people should understand the exaggerative nature of Pyongyang's statements. But he stressed the need to take those statements "seriously."

In an apparent angry response to the ongoing South Korea-U.S. joint military drills and the recent adoption of U.N. Security Council sanctions against the North for its latest provocations, Pyongyang has ramped up its rhetoric, threatening to strike the presidential office of Cheong Wa Dae and other key facilities in the South.

The reclusive state has also strengthened its propaganda to underscore its development of nuclear arms and their delivery systems. 

It has claimed to have secured the capability to mount a miniaturized nuclear warhead on a ballistic missile and the technology to allow its missile warhead to withstand the intense heat during atmospheric reentry. Seoul officials, however, doubt the claim.

As for the amount of fissile materials the North is thought to possess, Albright said that his institute has not secured any data to update its report released in October. 

Last year's ISIS report estimated that as of the end of 2014, the North had up to 34 kilograms of plutonium and up to 240 kg of highly enriched uranium, with which the North is capable of producing 15 to 22 nuclear bombs.

The Seoul government presumes that the North has accumulated some 40 kilograms of plutonium after it reprocessed spent fuel rods at least three times, in 2003, 2005 and 2009. Around 6 kg of plutonium is required to produce one nuclear bomb.

Seoul authorities also believe that the North could produce some 40 kilograms of HEU each year with some 2,000 operational centrifuges which it has claimed to have. To produce one HEU bomb, more than 15 kg of HEU is required. (Yonhap)