The Hill – Sen. Ben Cardin (D-Md.) said Monday, March, 30th that if Iran did not reach a satisfactory deal on its nuclear program, lawmakers would tighten sanctions on Tehran.
“The best case is to have an effective arrangement with Iran where they give up their nuclear weapon ambition,” said Cardin who sits on the Senate Foreign Relations Committee on MSNBC’s ” The Rundown with Jose Diaz-Balart.”
“If they don’t, sanctions will be tightened,” he added.
The senator said he hoped for a deal, but in the absence of one, “we will continue to isolate Iran as much as we can.”
Cardin said he hoped other nations would cooperate to reimpose other sanctions suspended during the talks.
“But we would pass stronger sanctions in the United States Congress and we would hope the international community would follow us,” he said. 
U.S. and international negotiators are trying to reach a framework for a deal that would seek Iran curb its nuclear program in exchange for sanctions relief by a Tuesday midnight deadline.
Iran claims its nuclear program is for peaceful purposes but the international community says it is developing weapons.
Cardin said Congress had a responsibility to be involved in overseeing any deal, and in lifting congressionally imposed sanctions on Iran.
“It was Congress that imposed the sanctions. Only Congress can permanently remove the sanctions,” he said.
Cardin said Congress should make sure that the agreement would prevent Iran from secretly developing a nuclear weapon in a short period of time.
He also argued for open inspections so that if Iran does not follow its commitments, U.S. and United Nations sanctions could snap back into place.
According to reports from Switzerland, where the negotiations are taking place, there are still disagreements between both sides, most recently on whether Iran should ship most of its enriched uranium which is needed to build a bomb outside of the country.