WASHINGTON – A Senate bill that would impose more sanctions on Iran could make it more difficult to successfully negotiate a deal to limit the country’s nuclear enrichment program, a group of experts said Wednesday.

On Monday the P5+1 countries — the five permanent members of the U.N. Security Council plus Germany — lifted some trade sanctions against Iran after they determined it had complied with a Nov. 24 agreement to limit its uranium enrichment program, a component to nuclear power creation.

The move is a first step towards an agreement to curb Iran’s nuclear capabilities that could conclude after six months of negotiations. The comprehensive deal is a longer term effort to reduce Iran’s overall enrichment capacity, with the goal of removing of all nuclear capability from Iran.

At a RAND Corporation panel discussion Wednesday, Arms Control Association Executive Director Daryl Kimball and others said  negotiations regarding nuclear fuel and equipment will be especially difficult.

The Senate bill to impose more sanctions against Iran is “well-intentioned” and also “misleading” because it adds to the original requirements of the November deal,  increasing the difficulty to conclude negotiations with Iran, he said.

“Depending on the circumstance, initial sanctions could decrease Iran’s motivation for going back to the negotiating table. So I think the wise thing to do is to give this effort all that it deserves and to evaluate where things stand at the end of six months,” Kimball said in an interview after the briefing. “Irani and leaders from the P5+1 group have a tough line to walk and not much time to do it in.”

The U.S. should hold off on economic sanctions to pressure the Iranian government into complicity, agreed Alireza Nader, a senior policy analyst at RAND Corporation. He said he does not believe the Nov. 24 deal improved Iran’s economy.

“The Iranian economy may be in a terrible condition, but the Iranian government is not on its knees,” Nader said.

Nader added, “I am not optimistic there will be a full détente.”

Kimball suggested that to reach a deal with Iran, the U.S. and its allies may have to compromise, possibly by requiring Iran to reduce the number of its centrifuges, devices that enrich uranium for nuclear use, by two-thirds instead of eliminating all of them.

“Iran is not going to agree to zero enrichments,” Kimball said.