The Iranians are building structures at their underground nuclear site despite the threat of retaliation by Trump. It comes as a change in administration might happen on January 6.

According to the United Arab Emirates, the Iranians are building at an underground nuclear facility in Fordo, knowing that the US is not pleased with its nuclear research that was the cause of the embargo. Satellite imagery is proof of suspected activity, said the Associated Press.

Ford was never disclosed by Iran publicly but is an undercover operation by designation. They kept it a state secret until the west discovered it in 2009. It was part of a nuclear deal in 2015 that they later violated, reported New York Post.

The purpose of structures is a mystery, and nukes are no.1 on Washington's threat list. Even with the clock ticking, if Trump stays, it will be of particular interest. Iran is rebuilding the Natanz nuke facility after an unknown explosion rocked it last July. Tehran said a saboteur caused the blast.

Jeffrey Lewis, an expert on Iran and specializing in studies about nukes' distributions, said the US and its allies would monitor the site and its partners in the Middle East. The activities at the site will be watched and checked if it leads to a deadly development later.

An Iranian mission to the United Nations was not able to give any remarks when asked for comment. Inspectors from the International Atomic Energy Agency are in Iran to check if they are fulfilling the Nuclear deal. Asked for comment (UN inspectors), they did not say anything yet about the inspection.

 Also: Iran Pursues Nuclear Production and Nuclear Submarines If the US Reset Sanctions

They started building at the nuclear facility in late September. Images obtained from Maxar by AP show construction activity on the northwest corner of the site, located near the City of Qom, which is 90 km. from Tehran.

 One of the photos on December 11 indicates a foundation that has many pillars for support. This kind of building technique is used for buildings that lie in earthquake-prone areas.

 Work being done on the Fordo's underground facility is at the northwestern end. Architects constructed the site into a mountain to shield the lab from airstrikes-only part of a complex of buildings for research and development of nuclear power in Fordo.

 One of the labs in the complex is the National Vacuum Technology Center. To master Vacuum technology is a prerequisite to making Iran's uranium-gas centrifuges, which will be crucial in enriching uranium. The Fordo site is vital to Iran in obtaining a workable nuclear technology that might be used for something else.

One Twitter account called Observer IL had it posted with the image of Fordo during construction. They cited the image as originating from South Korea's Korea Aerospace Research Institute.

 When AP sought out the Twitter user, he is a retired Israeli Defense Forces soldier with a civil engineering background. He has received online threats, and the Korea Aerospace Research Institute said they got the satellite photo.

When Iran violated the nuclear deal with the US at that time. With activities in their nuclear sites that started sanctions against them.

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