Undersecretary of state Wendy Sherman says 'pause' will let US see if talks over Iranian nuclear ambitions can 'gain traction'

The lead American negotiator in nuclear talks with Iran on Friday called for a delay in any new sanctions on the country, in order to let negotiations take hold.

"We think that this is a time for a pause, to see if these negotiations can gain traction," undersecretary of state Wendy Sherman said in a televised interview with Voice of America, the US foreign media service.

The Senate banking committee is debating whether to take up legislation, passed by the House last July, which could end Iranian oil exports. The White House hosted a meeting of Senate aides on Thursday, to argue against the measure.

The public nature of Sherman's statement was seen as a significant gesture to Tehran.

"I thought it was a very positive statement," said Reza Marashi, research director at the National Iranian American Council. "On this particular point about the sanctions, I think that's the most forward-leaning statement that I can recall an Obama administration official using, when discussing sanctions, at any time over the past four to five years.

"It was very specific. That not only sends a message to Congress but it also sends a message I think to the Iranians as well. That shows a certain level of seriousness to make these kinds of statements publicly."

The president has a great deal of leeway in enforcing sanctions – or not. Sherman called Congress a "partner" in sanctions, echoing language the White House used a day earlier.

"Congress has its prerogatives," she told Voice of America. "We don't get to control Congress, but we are having very serious discussions … We need them to continue to be effective partners to reach a successful conclusion, and I have trust that they will be."

Current sanctions against Iran, in place since 2011, have cut the country's oil exports by more than a million barrels a day, crippling the economy and creating food and medicine shortages. Additional sanctions would damage a fragile conversation, Marashi said.

"A train doesn't really run on two tracks," he said. "If you're pursuing a policy that moves down the sanctions track, how can you really truly be pursuing diplomacy as well? The Iranians have not exactly been productive at the negotiations table as the sanctions were escalated."

A meeting last week between Iran, Germany and the five permanent members of the UN security council was described by officials on both sides as productive. The P5+1 group is to meet again on 7 November.

An Iranian lawmaker claimed the country had halted the production of enriched uranium up to 20%, a crucial threshold for a weapons program, the New York Times reported Wednesday.

The multilateral talks followed a visit to UN headquarters in New York last month in which the Iranian president, Hassan Rouhani, hailed the United States as a "great nation" and offered to work rapidly to shape a nuclear accord.

Mistrust runs deep, however. UN inspectors have limited access to Iranian nuclear sites and Iran has taken steps to build a nuclear program capable of producing a weapon despite repeated denials of any desire to do so. On a visit to the White House last month the Israeli prime minister, Binyamin Netanyahu, urged President Barack Obama to leave the sanctions in place.