Acting US Defence Secretary Patrick Shanahan said on Tuesday that while regional threats from Iran remained high, action by the Pentagon had “put on hold” the chance of attacks on Americans.
“There haven’t been any attacks on Americans. I would consider that a hold,” Mr Shanahan said.
“That doesn’t mean that the threats that we’ve previously identified have gone away. Our prudent response, I think, has given the Iranians time to recalculate."
Later on Tuesday, Mr Shanahan, Secretary of State Mike Pompeo and Chairman of the Joint Chiefs of Staff Gen Joseph Dunford were to brief legislators on Iran.
The US military sent a carrier strike group, bombers and Patriot missiles to the Middle East this month after what Washington said were troubling indications of preparations for an attack by Iran.
Washington has tightened sanctions to push Tehran into making concessions beyond the terms of a 2015 multinational deal to curb Iran’s nuclear programme.
President Donald Trump pulled the US out of the deal in 2018.
Mr Trump warned on Monday that Iran would be met with great force if it attacked US interests in the Middle East.
US sources said Washington strongly suspected militias with ties to Tehran were behind a rocket attack in Baghdad’s Green Zone, near the American embassy.
“I just hope Iran is listening. We’re in the region to address many things, but it is not to go to war with Iran,” Mr Shanahan said earlier on Tuesday.
He said it was a period where the threat remained high and the focus was on making sure there was “no miscalculations by the Iranians".
US government sources said last week they believed Iran encouraged Yemen's Houthi rebels or militias based in Iraq to sabotage four tankers off the UAE.
Mr Pompeo said that the US had yet to reach a definitive conclusion that he could speak about publicly.
“But given all the regional conflicts that we have seen over the past decade and the shape of these attacks, it seems like it’s quite possible that Iran was behind these,” he told radio talk show host Hugh Hewitt.
The State Department said Mr Pompeo spoke with the Norwegian Foreign Minister, Ine Marie Eriksenon, on Tuesday.
They discussed the attack on the four vessels off Fujairah, one of which was registered in Norway.