By Patricia Zengerle
WASHINGTON (Reuters) - Top Obama administration officials have been pushing U.S. lawmakers hard to hold off on new sanctions over Iran's nuclear program, but some key lawmakers said on Wednesday they had not yet been convinced to support a delay.
Senator Bob Corker, the top Republican on the Senate Foreign Relations Committee and a member of the Senate Banking Committee, which is considering the sanctions package, said lawmakers were skeptical because they felt they had to push the White House to back strict sanctions on Tehran.
"It's incumbent upon them over the next 24 to 48 hours to persuade folks like me and others that the course of action they want to follow is a sound one," Corker told Reuters.
"I think ... because Congress had to push the administration into the sanctions regime in the first place, there is a degree of skepticism. But from my standpoint I'm certainly open to listening," he said.
Corker had a breakfast meeting on Wednesday with Secretary of State John Kerry. On Thursday, Kerry and Treasury Secretary Jack Lew were to hold a classified briefing on the status of talks with Iran for the Senate banking panel.
"The point that they are making is that they are at a point in these negotiations where they believe that additional sanctions coming out of the committee are counterproductive to the negotiations that are under way," Corker said.
The banking panel had been expected to vote on the sanctions in September, but held off after the Obama administration asked for a pause while negotiations with Tehran got under way.
Democratic Senator Tim Johnson, the banking committee's chairman, is waiting to hear from Lew and Kerry and will finish consulting with colleagues before making a decision on how to proceed, an aide said.
Senator Mark Kirk, a Republican member of the banking panel who is a strong backer of tougher sanctions, said he opposed any further delay.
"Every day the Senate delays consideration of new sanctions, Iran installs more centrifuges, enriches more uranium and improves its nuclear breakout capability," he said, referring to the ability to enrich uranium for use in a bomb.
"If Iran is capable of negotiating while violating international law, the United States should be equally capable of negotiating while imposing new sanctions pressure," Kirk said in a statement.
Washington and its allies believe Tehran is developing the ability to make a nuclear weapon, but Tehran says the program is for generating power and medical devices.
International talks over Iran's nuclear program revived after self-described moderate President Hassan Rouhani took office in August. The talks got under way this month and Iran, Britain, China, France, Russia, the United States and Germany will meet November 7-8 in Geneva for a second round.
Sanctions imposed in 2011 by Washington and the European Union have combined to slash Iran's oil exports by more than 1 million barrels a day, depriving Tehran of billions of dollars worth of sales and helping drive up inflation and unemployment.
The House of Representatives passed its version of a stiffer sanctions package in July by a 400-20 vote, seeking to slash Iran's oil exports by another 1 million barrels a day, to nearly zero.
(Additional reporting by Timothy Gardner; editing by Jackie Frank)