A senior official dismissed reports today that Washington plans to allow Iran access to the US financial system or to buy the latest Russian warplanes.
Responding to skeptical US lawmakers, Undersecretary of State Thomas Shannon insisted that the United States would maintain sanctions pressure on the Islamic republic.
But he confirmed that the State Department is attempting to "clarify" the terms of its financial sanctions to foreign banks now looking to do business with Iran.
"The rumours and news that has appeared in the press that the US is preparing to reinstate Iranian access to the US financial system are not true," he said.
In January, the United States and the European Union implemented their side of last year's Iran nuclear deal, lifting a raft of sanctions.
Under the accord, Iran had divested itself of its nuclear fuel stockpile, dismantled much of its enrichment capacity and put a bomb beyond its immediate reach.
In return, the West dropped many sanctions, giving Iran access to tens of millions of dollars in frozen assets and allowing it to double its oil exports.
But Washington maintains other sanctions designed to punish Tehran for maintaining a banned ballistic missile program and for arming Middle East militant groups.
Now Tehran is chafing under these ongoing sanctions, with hardliners accusing President Hassan Rouhani of having sold his country out for little reward.
And European and other international banks are returning only gingerly to the Iranian market, fearing their American operations will fall afoul of US prosecutors.
Secretary of State John Kerry and to a lesser degree President Barack Obama have hinted at sympathy for the complaints, insisting the United States will keep its side of the deal.
But this has led to concerns in Congress -- and conflicting reports in Washington -- that the administration is preparing new concessions to Iran.
As the Senate Foreign Relations Committee convened today, Senator Bob Corker asked Shannon to explain these "rumours out of the administration."
Shannon insisted that -- "as far as I know" -- there are no plans to allow Iran to use the US financial sector for transactions in dollars.
But he confirmed that the administration planned to reassure foreign banks seeking to do business with Iran about where they stand relative to US law.
