Plans to restore the 2015 nuclear agreement between the U.S. and Iran have taken an encouraging turn after productive talks in Vienna.

Officials say things have progressed to the point that negotiators have begun drafting proposals to get both nations to resume compliance with the original deal. The Russian envoy to the talks went on twitter to outline the next steps in the ongoing discussions.

Iranian President Hassan Rouhani added to the air of optimism around the negotiations, saying a deal could be imminent.

“The talks in Vienna have progressed about 60, 70% and if the Americans act within the framework of honesty, we will achieve results in a short time.”

President Biden has said he wants to restart the agreement that was in place until former president Trump pulled America out three years ago. Negotiations were stalled after an Iranian nuclear facility was attacked. It is widely presumed that Israel, which opposes the U.S. resuming its nuclear detente with Iran, was behind the attack. Iran responded by boosting its uranium production beyond the levels mandated by the old agreement and perilously close to what is needed to make a functioning nuclear weapon.

But since talks resumed last week, both sides report good-faith negotiating.