Iran returns to negotiations, with a nuclear crisis still looming large for Biden

Iran returned to negotiations over its nuclear program on Monday -- meeting for the first time in over five months.

Iran returned to negotiations over its nuclear program on Monday -- meeting for the first time in over five months, with the country's new hard-line government now in control.

Its chief negotiator emerged from closed doors bullish, as Tehran demands its concerns about continued U.S. sanctions be addressed first after former President Donald Trump withdrew the U.S. from the deal.

But the U.S. and the deal's European signatories are warning that after months of stalling, Iran is facing its last opportunity to revive the 2015 deal that placed constraints on its nuclear program in exchange for international sanctions relief.

A top European Union diplomat who is coordinating the indirect talks between the U.S. and Iran expressed some guarded optimism afterward -- and much urgency.