SEOUL: North Korea on Monday extended the window for its planned rocket launch by one week because of technical problems but stressed it was pushing on with the mission in the face of international condemnation.

A day after announcing a review of the original December 10 to 22 launch schedule, the Korean Committee of Space Technology said it was extending the window to December 29.

In a statement carried by the official Korean Central News Agency, the committee said scientists and technicians were still “pushing forward” with preparations for the mission. “They, however, found a technical deficiency in the first-stage control engine module of the rocket . . . and decided to extend the launch period.”

North Korea says the rocket launch is a peaceful mission aimed at putting a satellite into orbit. But the United States and its allies view it as a disguised ballistic missile test banned under UN resolutions prompted by the North’s nuclear tests in 2006 and 2009.

The window extension appeared to tally with South Korean media reports, citing government analysis of fresh satellite imagery, that North Korea was replacing a faulty component in the Unha-3 rocket.

In a separate report on Monday, the Chosun Ilbo—known for its comprehensive North Korean coverage—said a group of Iranian missile experts was in North Korea offering technical assistance for the planned launch.

The Iranians were invited after Pyongyang’s last long-range rocket launch in April ended in failure, the newspaper said, citing a Seoul government official.

Earlier this month, Japan’s Kyodo news agency quoted a western diplomatic source as saying Iran had stationed defense personnel in North Korea since October to strengthen cooperation in missile and nuclear development.

North Korea and Iran are both subject to international sanctions over their nuclear activities and their governments share a deep hostility towards the United States.

Leaked US diplomatic cables in 2010 showed that US officials believe Iran has acquired ballistic missile parts from North Korea. A 2011 United Nation sanctions report said the two countries were suspected of sharing ballistic missile technology.