The US has reportedly said that Washington will not be able to restrain Israel if it attacks again.

The Axios news website has cited a US official saying: “We told the Iranians: We won’t be able to hold Israel back, and we won’t be able to make sure that the next attack will be calibrated and targeted as the previous one.”

The report quoted the official as saying the message had been conveyed directly to the Iranians, though the Israeli source said a message was passed to Tehran via Swiss intermediaries.

Meanwhile, US Central Command (Centcom) announced on Saturday that B-52 bombers had arrived in the Middle East amid the Iranian threats against Israel and the United States.

“B-52 Stratofortress strategic bombers from Minot Air Force Base’s 5th Bomb Wing arrived in the US Central Command area of responsibility,” Centcom tweeted, with an accompanying picture of one of the massive planes on final approach.

Defence Secretary Lloyd Austin announced the deployment of the bomber aircraft on Friday, along with US Navy warships.

The Associated Press, citing four US and defence officials, reported on Friday that Austin ordered several B-52 Stratofortress bomber aircraft, tanker aircraft and Navy destroyers to the Middle East.

The US did not provide specific numbers of planes and ships sent to the region.

A US official told AP that Austin ordered the deployment of the destroyers, capable of shooting down ballistic missiles, to replace the USS Abraham Lincoln aircraft carrier and its strike group of three Naval destroyers, which are scheduled to depart the Mideast in mid-November for their home port of San Diego.

The Lincoln and two of its destroyers are stationed in the Gulf of Oman, and the third destroyer is with two other warships in the Red Sea.

Eventually, the USS Harry S. Truman aircraft carrier and its three warships will move to the Mediterranean Sea, but not before the Lincoln departs, thus the three destroyers will fill in the gap.