Two top Senate Democrats have called for an investigation into Elon Musk's reported contacts with Russian President Vladimir Putin and his top aides.
The lawmakers have urged the Pentagon and Justice Department to determine whether Musk's alleged relations with a US adversary while holding major government contracts puts national security at risk.
The Wall Street Journal reported last month that the world's richest person has had "multiple, high level conversations" with Putin since 2022, which the Kremlin has denied.
Musk wrote on his X platform on Friday that he's "going to find out who's making these accusations and nuke them".
The two Democrats - Rhode Island Senator Jack Reed, chairman of the Senate Armed Services Committee, and New Hampshire Senator Jeanne Shaheen, a senior Democrat on the Armed Services and Foreign Relations Committees sent a letter on Friday to Attorney General Merrick Garland and Defence Department Inspector General Robert Storch raising "serious questions regarding Mr Musk’s reliability as a government contractor and a [security] clearance holder".
The multi-billionaire claims to hold a top-secret level clearance and his SpaceX company - one of the main contractors to the National Aeronautics and Space Administration (Nasa) - is deeply embedded in the federal government's defence and intelligence infrastructure.