Leading Democratic and Republican senators are crafting legislation to reinstate the full force of sanctions and impose new ones if Iran doesn't make good on its pledge to roll back its nuclear program, brushing aside the Obama administration's fears about upending its diplomatic momentum.
Sens. Bob Menendez, D-N.J., and Mark Kirk, R-Ill., hope to have the bill ready for other lawmakers to consider when the Senate returns Dec. 9 from its two-week recess, according to legislative aides. Many in Congress are skeptical, if not outright hostile, to the deal reached by Iran and world powers over the weekend in Geneva.
The Kirk-Menendez measure would require the administration to certify every 30 days that Iran is adhering to the terms of the six-month interim agreement and that it hasn't been involved in any act of terrorism against the United States.
(Read more: Iran sanction pain to remain under deal)
Without that certification, sanctions worth more than $1 billion a month would be reimposed and new sanctions would be added. The new measures would include bans on investing in Iran's engineering, mining and construction industries and a global boycott of Iranian oil by 2015. Foreign companies and banks violating the sanctions would be barred from doing business in the United States.