US President Barack Obama sought to build political support beyond Washington for the Iran nuclear agreement, urging thousands of supporters from across the country to push Congress to support the deal, according to USA Today.

"You guys have to get more active and loud and involved and informed," Obama told backers on a conference call arranged by the White House.

Obama told the supporters that this is "a very good deal that we should be proud of," Obama said.

"Iran under this agreement can never get a nuclear weapon," he said.

The call included members of organizations that have worked with the White House on past issues.

Congressional Republicans have attacked the proposal, saying that the proposed inspection rules give Iran too much room to cheat.

Some Democrats are also skeptical. At least one House Democrat — Rep. Grace Meng of New York — has come out against the agreement, saying that "I believe the inspections procedures set forth are flawed."