Biden has named one of the original negotiators of the 2015 Iran nuclear deal to spearhead the new administration's efforts to revive diplomacy with Iran as its special envoy.

Robert Malley is a career diplomat who served both the Obama and Clinton White House is.

He was also at the table, seated across from the Iranians when the 2015 deal was finalized in Switzerland.

Malley's now entering one of the most perilous and politically divisive challenges facing the U.

S government after four years of rapidly worsening relations between the two countries under President Trump and crises that at one point brought them to the brink of war on hand because it won't be easy.

On Friday, one of the other men that was at that table back in 2015, Iran's foreign minister, Javad Zarif, reiterated Tehran's demand that it will not reverse the steps that's taken to revive its nuclear program unless Washington lifts sanctions first.

Biden administration has previously said that Iran has to make the first move.

Trump abandoned the nuclear treaty back in 2018.