By Andy Sullivan
WASHINGTON (Reuters) - U.S. lawmakers said on Sunday they aim to tighten sanctions on Iran to ensure the Obama administration does not give away too much in a planned deal to stop Tehran's nuclear development program.
The remarks are further evidence of the skepticism the Obama administration faces at home and abroad in its efforts to build a dialogue with the Islamic republic after more than three decades of deep mistrust.
"We know the sanctions have gotten us here and we're worried we're dealing away our leverage," Bob Corker, the top Republican on the Senate Foreign Relations Committee, said on NBC's "Meet the Press."
That committee will move ahead with additional sanctions this week to keep the pressure on Iran as talks continue, said Democratic Senator Bob Menendez, the committee's Democratic chairman.
"My concern here is that we seem to want the deal almost more than the Iranians," Menendez said on ABC's "This Week."
The United States and its allies narrowed their differences with Tehran over the weekend, but were not able to reach a deal as France believed the proposal did not adequately neutralize the risk of an Iranian atom bomb. Iran says its nuclear program is peaceful in nature. The two sides have held two rounds of talks and plan to meet again in Geneva on November 20.
"I've never been more worried about the Obama administration's approach to the Mideast than I am now," Republican Senator Lindsey Graham said on CNN's "State of the Union."
"Thank God for France," he added.
U.S. Secretary of State John Kerry, who participated in the talks, said other countries involved in the talks share France's concerns and the United States would not agree to a deal that it found inadequate. Russia, China, Britain and Germany have also been involved in the negotiations.
"We are not blind, and I don't think we're stupid. I think we have a pretty strong sense of how to measure whether or not we are acting in the interests of our country and of the globe," Kerry said on NBC's "Meet the Press."
The deal under discussion would freeze Iran's higher-grade uranium enrichment for six months and open up the program to U.N. anti-proliferation inspectors. During that time, Iran and the six powers would negotiate a permanent agreement aimed at ensuring that none of Iran's nuclear activities could be diverted towards bomb-making.
In exchange, Tehran would obtain phased and initially limited relief from sanctions.
One possible concession would allow Iran access to about $50 billion that has been frozen in foreign accounts for years. Allies could also temporarily relax restrictions on precious metals trading, and Washington could ease pressure on countries not to buy Iranian oil.
Kerry said the United States will not reduce the "core architecture" of the oil and banking sanctions.
"Nobody has talked about getting rid of the current architecture of sanctions. The pressure will remain," he said. He added that the United States has not ruled out the use of military force if needed.
At the same time, "it seems to me you've got to do something that indicates your good faith," he said.
Negotiators have limited political room to maneuver as there is hard-line opposition to any diplomatic thaw both in Tehran and in Congress. Israel, an important U.S. ally which considers Iran's nuclear drive a mortal threat, has condemned the interim deal taking shape.
Graham said lawmakers from both parties will soon introduce a resolution that would call on Iran to turn over all of its highly enriched uranium to the international community and dismantle its centrifuges used in the enrichment process.
Corker and Menendez also serve on the banking committee, which had planned to meet this week to weigh a further tightening of financial sanctions. Corker said Democrats have canceled that meeting.
Kerry is due to brief Congress on the talks this week.
While lawmakers support the diplomatic efforts, "we're also concerned about an administration that seems really ready, always, to jump into the arms of folks and potentially deal away some of the leverage we have," Corker said.
(Additional reporting by Charles Abbott and Vicki Allen; Editing by Sandra Maler and Eric Walsh)