In this Dec. 29, 2016 file photo, released by the semi-official Iranian Students News Agency (ISNA), a long-range S-200 missile is fired in a military drill in the port city of Bushehr, on the northern coast of Persian Gulf, Iran.

Despite a landmark international deal to halt its nuclear program, Iran is allegedly “cheating” by conducting research into nuclear weaponry.

An Iranian opposition group based in Washington has made the claims, saying that the regime is researching components such as bomb triggers and enriched uranium, as well as carrying out engineering and weaponization testing at a walled military complex south of Tehran.

This location is declared off-limits to inspectors, the National Council of Resistance of Iran (NCRI) and its main operational arm, the People’s Mujaheddin of Iran (MEK) said in a statement carried by the Washington Times.

“This is the site that has been kept secret,” said Alireza Jafrazadeh, NCRI’s Washington office deputy director. “There is secret research to manufacture the bomb and basically cover up the real activities of the Iranian regime.”

The Joint Comprehensive Plan of Action (JCPOA) signed between Iran and world powers restricts its nuclear fuel enrichment for 10 years.

US Secretary of State Rex Tillerson branded the Iran nuclear deal a failure Wednesday as President Donald Trump ordered a review of how Washington is countering the threat from Tehran.

The State Department admits that Iran has so far maintained its side of the bargain it struck with world powers in 2015 to curtail its nuclear program in exchange for sanctions relief.

But Tillerson argued the accord had just been a way of “buying off” the regime and would only delay its development of a nuclear weapon that could threaten its region and the world.

“The Trump administration has no intention of passing the buck to a future administration on Iran,” Tillerson told reporters.

US Secretary of State Rex Tillerson.