The dispute over uranium enrichment is the flashpoint in U.S.-Iran talks, with Tehran refusing to scale back and Washington warning of weaponization.

Iran’s top diplomat is insisting that Tehran will never stop enriching uranium, further underlining the Islamic Republic’s red line in negotiations with the United States over its rapidly advancing nuclear program.

Iran's top diplomat insisted Wednesday that Tehran will never stop enriching uranium, reinforcing the Islamic Republic's hard line ahead of a new round of indirect talks with the United States over its fast-advancing nuclear programme.