US eases tone on Iran

President Donald Trump's administration charged Tuesday it was  "quite possible" Iran was responsible for the sabotage of Gulf oil interests but said its robust response had stopped potential attacks on Americans.

Top Trump officials appeared to be toning down weeks of fiery warnings to Iran before delivering a classified briefing to the full Congress, where opposition Democrats have accused the administration of hyping intelligence and pushing the United States dangerously close to war.

Secretary of State Mike Pompeo said the United States has not made  "a definitive conclusion" that can be presented publicly over the sabotage of oil tankers off the United Arab Emirates or drone strikes on a crude pipeline in Saudi Arabia.

Pompeo told conservative radio host Hugh Hewitt before heading to Capitol Hill that Iran might be behind the attacks

John Bolton, Trump's hawkish national security advisor, earlier this month warned of  "unrelenting force" if Iran strikes US interests as he announced the deployment to the region of an aircraft carrier strike group, followed by nuclear-capable B-52 bombers.

Acting Defense Secretary Patrick Shanahan, who was joined at the briefing by the US military chief, General Joseph Dunford, said the US response had made an impact.

"I think our steps were very prudent and we've put on hold the potential for attacks on Americans," Shanahan told reporters.

"I'd say we're in a period where the threat remains high and our job is to make sure that there is no miscalculation by the Iranians," he said.