Pyongyang: North Korea's five-day window to launch a rocket opened on Thursday with no confirmed firing, but Asian countries remained on alert as Washington rallied world opinion against the communist state.

The morning timeframe in which North Korea plans to launch its 30-metre rocket came and went with no sign of liftoff from a newly built space centre on the country's northwestern Yellow Sea coast.

But the North says the Unha-3 (Galaxy-3) rocket, ostensibly carrying a satellite payload, could go up any day between now and Monday to coincide with Sunday's centenary of the birth of its founding leader Kim Il-Sung.

North Korea is now led by a third generation of the Kim dynasty in the youthful form of Kim Jong-Un, who has been awarded an array of titles including yesterday chairman of the all-powerful Central Military Commission.

Fighter jets were heard roaring across Pyongyang's overcast skies early today as the showcase capital stepped up preparations for mass festivities on Sunday to mark the 100th anniversary.

North Korea says its rocket launch is not a banned missile test and that it has every right to send the satellite up, as it promotes the untested leadership of Jong-Un, who succeeded his late father Kim Jong-Il in December.

Lee Yun-Keol, a high-ranking North Korean defector who now heads a think-tank in Seoul, told AFP that he had obtained Kim Jong-Il's last will and testament, which urged the state\ to develop weapons of mass destruction.

(Agencies)