Iran Accelerates Underground Nuclear Facility Construction Near Natanz, US Prepares Response

Construction activity has significantly increased in 2026 at an underground facility known as Pickaxe Mountain, located near Iran's Natanz nuclear complex, according to a new analysis of satellite imagery by the Center for Strategic and International Studies (CSIS) reported by CNN. Analysts examining six years of images concluded that construction has moved from earthworks to interior outfitting and reinforcement. CSIS noted that 2026 saw the most intense road activity at the site, with tunnel entrances reinforced, an internal road network established, and excavated soil leveled and partially removed. Researchers emphasize that the ongoing work suggests the complex is likely not yet ready for uranium enrichment, even if that is its intended purpose.

Pickaxe Mountain is situated approximately two kilometers from Natanz and extends deep into a granite mountain. CSIS suggests its most probable uses include the production and assembly of centrifuges, housing a uranium enrichment facility, or serving as a protected site for other nuclear program activities, such as metallic uranium production. This comes after Israeli intelligence reportedly informed the U.S. that Iran might have moved thousands of centrifuges and their components into tunnels, though this has not been independently verified.

Concurrently, the U.S. military is reportedly accelerating efforts to develop capabilities for striking deeply buried underground targets. Shortly before a U.S. operation against Iran, a U.S. Defense Threat Reduction Agency official approved a $1.2 million contract to refurbish a special underground testing facility at White Sands Missile Range in New Mexico, citing preparations for live-fire testing against "rapidly evolving threats." The U.S. Air Force is also developing the Next Generation Penetrator bomb to replace the GBU-57 Massive Ordnance Penetrator, aiming to hit even deeper targets.

CNN, citing an informed source, reports that U.S. military operational plans exist to strike Pickaxe Mountain. However, it remains uncertain whether current large non-nuclear munitions can penetrate deep enough to destroy the facility. U.S. President Donald Trump recently reiterated the possibility of a U.S. strike on Pickaxe Mountain "very soon."