Acting US Defence Secretary Patrick Shanahan says while threats from Iran in the Middle East remain high, deterrence measures taken by the Pentagon had "put on hold" the potential for attacks on Americans.
It was unclear exactly what Mr Shanahan meant and Pentagon officials could not immediately clarify whether the threat from Iran had been diminished.
"There haven't been any attacks on Americans. I would consider that a hold," Mr Shanahan told reporters.
Acting US Defense Secretary Patrick Shanahan says threats from Iran in the Middle East remain high. Source: AAP
"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," he said.
Later on Tuesday, Mr Shanahan along with Secretary of State Mike Pompeo and Chairman of the Joint Chiefs of Staff Joseph Dunford will brief lawmakers on Iran.
The US military deployed a carrier strike group, bombers and Patriot missiles to the Middle East earlier this month in response to what Washington said were troubling indications of possible preparations for an attack by Iran.
Rhetoric between Tehran and Washington has escalated in recent weeks as the US tightened sanctions with what it said was the goal of pushing Iran to make concessions beyond the terms of a 2015 multinational deal to curb Iran's nuclear program. President Donald Trump pulled the United States 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 government sources said Washington strongly suspected Shi'ite militias with ties to Tehran were behind a rocket attack in Baghdad's Green Zone.
"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.
President Donald Trump pulled the United States out of the Iran deal in 2018. Source: AAP
He added that 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 told Reuters last week they believe Iran encouraged Houthi militants or Iraq-based Shi'ite militias to carry out attacks on tankers off the United Arab Emirates.
Secretary of State Pompeo said in a radio interview that the United States had yet to reach a definitive conclusion he could speak publicly about.
"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 the Hugh Hewitt show.
The US Navy conducted exercises in the Arabian Sea after warning of a threat from Iran. Source: AP
The State Department said Pompeo spoke with his Norwegian counterpart on Tuesday and discussed an attack on a Norwegian-flagged vessel off Fujairah in the United Arab Emirates.
