Fox News has exclusively obtained satellite imagery revealing what an opposition group says is a previously undisclosed Iranian nuclear weapons facility — raising fresh concerns amid ongoing negotiations between Tehran and the Trump administration.

The newly identified site, located in Iran’s Semnan Province, is far from the regime’s already-known nuclear facilities. According to the National Council of Resistance of Iran (NCRI), intelligence gathered from sources inside the country points to a sprawling compound covering nearly 2,500 acres.

Code-named the “Rainbow Site” by Iranian officials, the facility has reportedly been in operation for more than a decade, masked as a chemical production company known as Diba Energy Siba.

According to NCRI sources, the primary function of the Rainbow Site is the extraction of tritium — a radioactive isotope used to enhance nuclear weapons. Unlike uranium enrichment, tritium has virtually no peaceful or commercial applications, casting further doubt on Iran’s longstanding claims that its nuclear ambitions are solely for energy or civilian use.

The revelations come as the Trump administration navigates sensitive negotiations with Tehran. When asked about the U.S. position on whether Iran can maintain a nuclear enrichment program short of weapons development, President Donald Trump told reporters on Wednesday, “We haven’t made that decision yet. We will, but we haven’t made that decision yet.”