File photo of US Secretary of State John Kerry.
The United States on Friday denied that blacklisting more than a dozen companies and people accused of evading sanctions against Iran had violated a landmark nuclear deal reached with Tehran.
And a State Department spokeswoman defended the surprise announcement that caused Iran to walk out of talks in Vienna, saying Iranian officials had been given a heads-up.
"We have been very clear throughout the entire negotiating process with the Iranians that we were going to continue designations. They knew that," spokeswoman Marie Harf told reporters.
Under a November 24 deal reached in Geneva between Iran and six global powers, Tehran agreed to freeze parts of its nuclear enrichment program for six months in return for $7 billion in sanctions relief to help its crippled economy.
The United States also agreed not to unveil any new nuclear sanctions, and US officials have insisted that Thursday's designations of sanctions-busting companies and individuals were imposed under legislation already on the books.
But Iran on Friday abruptly withdrew from technical talks on implementing the agreement, saying that Washington had violated "the spirit" of the Geneva deal.
Tehran was now weighing the "appropriate response," chief negotiator Abbas Araqchi told the Fars news agency as his team headed back to Tehran from Vienna.
But Harf dismissed the break in the talks, saying the negotiators had always planned to return home to consult with their governments.
US Secretary of State John Kerry said Friday during a visit to Jerusalem that the talks were expected to continue "in the next few days."