The tentative proposal would also allow Iran to receive assistance from regional countries to enable Tehran to build a civilian nuclear program, granting Tehran access to as much as $30 billion.

The U.S. was one of the parties to the 2015 nuclear deal in which Iran agreed to limits on its uranium enrichment program in exchange for sanctions relief and other benefits.

Attacks also destroyed facilities linked to nuclear development, including the headquarters of Iran’s defence research agency, and buildings at a university in Tehran believed to be associated with the nuclear programme.