US officials said the US military used a long-range B-1 bomber in strikes on Iran on Tuesday for the first time since fighting with Iran resumed 12 days ago.

"Axios" considered that the use of B-1 bombers, capable of carrying about 24 two-thousand-pound (about 900 kg) bombs or dozens of cruise missiles, is an indicator of a major escalation and expansion of the US military campaign.

The B-1 bomber can fly at supersonic speeds at low altitudes while carrying a larger bomb load than any other type of bomber.

As the US military buildup in the region continues, President Donald Trump is still considering a return to large-scale combat operations against Iran. US and Israeli officials say this could happen "within days."

The B-1 bomber took off to carry out its mission from an air base in the United Kingdom, and was tracked via aircraft tracking websites, according to Axios.

The US Central Command (CENTCOM) did not mention the B-1 bomber's mission in its statement Tuesday regarding the strikes carried out that day.

CENTCOM said in its statement that its forces targeted "Iranian military operations centers, naval capabilities, aircraft hangars, drone storage facilities, and military logistics infrastructure, aimed at weakening Iran's ability to threaten commercial shipping in the Strait of Hormuz."

It was not clear what the B-1 bomber specifically targeted, and whether the large mission was more effective than other strikes carried out in recent days.

The United States conducted several missions using B-1 bombers during Operation "Epic Fury," targeting missile bases, command centers, weapons storage facilities, and air defense systems.

Despite the expansion of US strikes, the Iranian regime does not appear to have changed its position on the Strait of Hormuz. Some US defense officials said Iran's military capability around the Strait of Hormuz is "virtually nonexistent," while others believe Iran is still capable of attacking ships in the area.

On Wednesday, Trump threatened to bomb bridges and power stations, including inside Tehran, if Iran attacks more ships in the Strait of Hormuz.

Mediator efforts

US officials said Qatari mediators are still holding talks with US, Iranian, and Omani officials in an attempt to reach a new agreement to reopen the Strait of Hormuz and stop the fighting.

A regional source indicated that the Iranian leadership did not accept the latest proposal put forward by the mediators. It remains unclear how long Trump will give diplomatic efforts a chance.

Trump said in a speech Wednesday evening in Georgia: "They are being hit very hard, and they want to make a deal."

He added: "But I say they are not ready to make a deal, because every time they make a deal they want to change it and everything else. They are not ready. They will be ready very soon."