Updated

Missile experts from Iran are in North Korea to help Pyongyang prepare for its rocket launch, according to reports.

Amid increasing global concern over the rocket launch, believed by the U.S. and its allies to be an illegal missile launch, Japan's Sankei Shimbun newspaper claimed today a 15-strong delegation from Tehran has been in the country advising the North Koreans since the beginning of March.

The Iranian experts include senior officials with Iranian rocket and satellite producer Shahid Hemmat Industrial Group, the daily said.

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The Iranians brought a letter from Iran President Mahmoud Ahmadinejad to North Korean leader Kim Jong-Il stressing the importance of cooperating on space technology, it added.

As tensions increase ahead of the rocket launch, Japan's Air Self-Defense Force began deploying units capable of shooting down a rocket to the northern prefectures of Akita and Iwate, according to local media.

Early today, units carrying Patriot Advanced Capability-3 missiles left a base in central Japan and will arrive at the northern prefectures on Monday, according to Japan's national broadcaster NHK.

Tokyo gave its military the green light to shoot down any incoming North Korean rocket on Friday.

Pyongyang has said it will launch a communications satellite over northern Japan between April 4 - 8, but the U.S. and its allies in the region believe the secretive regime is actually planning illegally to test a long-range Taepodong-2 missile that could reach North America.

Click here to read the full story from the Sunday Times.