By Patricia Zengerle
WASHINGTON (Reuters) - Two weeks after efforts to kill the Iran nuclear deal failed in the U.S. Congress, lawmakers were still developing legislation on Thursday seeking to influence, or undermine, the international agreement.
The House of Representatives voted 251 to 173 on Thursday for a measure that would bar President Barack Obama from waiving any sanctions on Iran under the pact until $40 billion has been paid to Americans deemed to be victims of Iranian-backed terrorism.
The measure passed the Republican-led House largely along party lines, with Republicans in favor and Obama's fellow Democrats opposed.
It was largely a show vote. The White House said on Wednesday that Obama would veto the measure if it passed, and that he would oppose any legislation that would undermine the nuclear agreement reached in July between the United States, five other world powers and Iran.
The measure also would be unlikely to advance in the Senate, where Democrats last month gathered enough votes to protect the deal itself.
The deal aims to curb Iran's nuclear program and keep it from developing nuclear weapons, while easing sanctions on Tehran.
However, opponents of the deal, who included every Republican in the U.S. Congress, say they want to underscore their opposition to the pact and send the message that the next U.S. president might not support it. The next president will take office in January 2017 after elections in November 2016.
Separately, a group of nine Democratic U.S. senators, two of whom voted against the nuclear agreement last month, introduced legislation on Thursday that they said would strengthen the pact.
Among other things, the Iran Policy Oversight Act authorizes additional security assistance for Israel, including accelerated development of missile defense systems with Israel, additional financing and ordnance and delivery systems to counter non-peaceful nuclear activities by Iran.
The measure would also require reports from the administration that would include details on Iran's use of funds received from any sanctions relief and on Iran's nuclear research and development.
The senators said they were in talks with Republicans about advancing the legislation, but there was no indication of when it might be brought up for any vote.
(Reporting by Patricia Zengerle; Editing by Frances Kerry)