Though he once vigorously opposed its involvement, President Barack Obama has signed legislation that gives the US Congress the power to review and potentially reject a nuclear deal with Iran.

Achieving a deal with Iran is a central element of Obama's foreign policy ambitions, and the new law imposes conditions on his ability to act on his own. He signed the measure without ceremony on Friday at the White House.

Negotiators from the US, China, France, Russia, Great Britain and Germany are seeking a deal with Tehran by the end of June. Israel and some Persian Gulf nations worry Iran is simply delaying its nuclear ambitions to get economic sanctions lifted.

The legislation would bar Obama from waiving congressional sanctions for at least 30 days while lawmakers examine any final deal. Congress would have to pass a resolution of disapproval to reject an agreement, an action Obama likely would veto. Obama had initially threatened to veto legislation that placed conditions that Iran would never accept.

Speaking to a Jewish congregation in Washington yesterday, Obama sought to offer assurances that he wanted an ironclad compact.

"I will not accept a bad deal," he said. "This deal will have my name on it, so nobody has a bigger personal stake in making sure that it delivers on its promise."



Sen Bob Corker, the Tennessee Republican who chairs the Senate Foreign Relations Committee and helped write the legislation, said the Obama administration must make sure it addresses concerns raised by Congress.

"Our negotiators should take advantage of the added leverage to force further concessions from the Iranians so that any agreement reached is verifiable, enforceable and can assure the American people Iran will not be able to develop a nuclear weapon," he said.

Obama also signed legislation that prevents the government from subjecting death benefits for the families of fallen police officers to federal income tax. Sponsors of the bill, which received unanimous support in the House and Senate, said the law would ensure that the families of public safety officers killed on duty receive their full benefits.