The U.S. hasn't been able to slow the steady stream of foreign companies touring Iran, but senior Obama administration officials say they are keeping them from signing business deals while nuclear negotiations continue.
The administration's top Iran negotiator, Wendy Sherman, and its sanctions chief, David Cohen, reassured skeptical senators Tuesday that they are holding the line on sanctions while diplomats from the United States and Iran try to cobble together a final agreement to curtail Iran's nuclear program.
"We will continue to respond to Iran's efforts to evade our sanctions wherever they may occur," Cohen said at a Senate Foreign Relations committee hearing Tuesday.
The interim nuclear deal signed in Geneva late last year went into effect in January and lifts some sanctions on Iran's petrochemical and auto industries, but leaves the vast majority of the punitive measures in place.
Skeptics of the talks are concerned that foreign companies are so eager to resume business with Iran that they'll take advantage of any Western sanctions relief, no matter how limited, completely undermining the sanctions regime that has crippled Iran's economy and brought Tehran to the negotiating table.
"Who's job is it going to be to put the genie back in the bottle when this thing fails?" Sen. James Risch (R-I.d.) asked at the hearing.
Iranian President Hassan Rouhani's courting of the international business community has stoked those fears. At the elite World Economic Forum meeting in Davos, Switzerland, Rouhani extended an invitation to the business people and political leaders gathered there to visit Iran and "witness the extensive fields for investment."
German, French and Italian companies are beating a path to Tehran, putting the administration in an awkward position at home, where officials are trying to reassure U.S. lawmakers that sanctions haven't been weakened by the interim deal.
In response, administration officials have been traveling the world to warn companies and governments not to rush back into Iran.
"As part of this effort, over the last six weeks I have traveled to the U.K., Germany, Italy, Austria, Turkey and the United Arab Emirates carrying this message: 'Iran is not open for business,'" Cohen said.
Not all American allies appear to be listening. A French trade delegation of more than 100 businesspeople went to Tehran this week to meet with officials and explore possible future opportunities. The group, the largest European delegation to visit Iran in 30 years, included French energy giant Total, carmaker Renault and engineering firm Alstom. Sherman said Kerry communicated American concerns about the trip to French Foreign Minister Laurent Fabius and told him that those visits weren't helpful.
After reports surfaced about a possible Iranian oil deal with Russia, U.S. officials warned Moscow that it could be sanctioned if the agreement went through. Sherman said those warnings have been successful so far. "My own sense of this is...that nothing will move forward at this time," Sherman said.
For the moment, she said most of the businesses visiting Iran are just looking, not inking new deals.
"Most of these delegations appear to be going to get themselves in line for the day that in fact a comprehensive agreement is reached, if it is reached," Sherman said.
One potential upside: the clear signs that Western multinationals want to return to Iran could prompt Iranian business people to pressure Rouhani to make a deal so business can resume.
"Although we don't want people to go because we think it does send the wrong message, if they do go, it puts pressure, perversely, on the Rouhani administration," Sherman said.