MOSCOW, June 20 (RIA Novosti) - A Russian presidential aide said Tuesday the "imminent" launch of a North Korean ballistic missile was largely a matter of psychology.

It is widely believed that Pyongyang is stepping up preparations to fire the Taepodong-2, a two-stage ballistic missile with a range of up to 6,000 kilometers (3,700 miles) that could in theory deliver a warhead to Alaska, USA.

"Let them launch it first and then we will see whether it will fly, where it will fly, and whether it can reach its target in the first place," Igor Shuvalov said.

Last month, a U.S. space satellite spotted a booster rocket and several fuel tanks on a launch pad in the east of the communist country, which has claimed it already has a nuclear capability.

According to regional media reports, the missile could be fired at any moment.

Pyongyang last tested a long-range missile in 1998, when it fired the Taepodong-1 missile, with a range of 2,000km (1240 miles), over Japan. The missile landed in the Pacific Ocean, causing a shock in Tokyo.