North Korea has not moved a long-range rocket to a launch pad yet and the chances of the communist nation conducting a launch around next month's ruling party anniversary are not high, a diplomatic source in Washington said Monday.

"As of September 6th, it appeared that there was no rocket present at the launch tower," the source told Yonhap News Agency on condition of anonymity, referring to the North's recently upgraded Sohae Satellite Launching Station on the country's northwest coast.

"There is an outside chance it is being hidden there under an environmental cover but odds are there is nothing there. Nor are there any other signs at the facility of launch preparations. And it's only three weeks until the anniversary." he said.

Speculation has persisted that the North could launch a long-range rocket from the site in October to mark the 70th anniversary of the founding of the Workers' Party after a recent upgrade enabled the launch site to handle bigger rockets.

Fueling the speculation, the North's National Aerospace Development Administration said Monday night local time that the country's rocket and satellite scientists are working very hard to mark the party anniversary with greater scientific achievements.

"The world will clearly see a series of satellites of (North) Korea soaring into the sky at the times and locations determined by the Central Committee of the Workers' Party of Korea," the KCNA reported in an English statement, without elaborating.

The North also claimed it has the right to launch rockets for peaceful purposes.

Pyongyang has long been accused of using long-range rocket launches as a pretext for test-firing intercontinental ballistic missiles. Experts say long-range rockets and ICBMs are basically the same with differences only in payloads.

The North is believed to have honed advanced ballistic missile technologies through a series of test launches, including a 2012 launch that succeeded in putting a satellite into orbit. That test is considered the most successful so far.

The test also sparked fears that the North has moved closer to ultimately developing nuclear-tipped missiles that could potentially reach the United States mainland. The country has so far conducted three underground nuclear tests: in 2006, 2009 and 2013. (Yonhap)