Security forces and rescue teams walk past a damaged building at a site hit by a shell in Bnei Brak, on the eastern outskirts of Tel Aviv. (AFP)

The US military referred questions seeking comment to the White House, which said that all announcements regarding troop deployments would be issued by the Pentagon.

White House spokeswoman Anna Kelly said, "As we have said, President Trump always has all military options available."

One source told Reuters that no decision has been made to send forces inside Iran itself, but these troops will enhance capabilities in preparation for any potential operations in the region in the future.

Another source said the Pentagon is preparing to send between 3,000 and 4,000 troops.

The troop deployment follows a Reuters report on March 20 about the United States’ decision to send thousands of Marines and sailors to the Middle East aboard the US ship Boxer, an amphibious assault ship, along with its Marine expeditionary unit and accompanying warships.

Before the additional forces are sent, 50,000 US troops are already stationed in the region.

News of the expected deployment comes two days after Trump postponed his threats to strike Iranian power plants, saying that “productive” talks had taken place with Iran.

However, Iran denied holding any talks with the US president.

The United States has carried out attacks on 9,000 targets inside Iran since the start of US and Israeli military operations on February 28.

A US official said that 13 American soldiers have been killed so far in the war, while 290 others have been injured. Ten soldiers remain in critical condition, and 255 have returned to service.

Trump is planning his next moves

Earlier sources reported that the US military is considering options in the war with Iran, including securing the Strait of Hormuz, possibly by deploying American forces along the Iranian coast.

The Trump administration has also discussed options for sending ground troops to Iran’s Kharg Island, which handles up to 90 percent of the country’s oil exports.

The 82nd Airborne Division specializes in parachute assault operations and is capable of deploying within 18 hours of receiving orders.

Any use of US ground forces, even in a limited mission, could pose significant political risks for Trump, given declining American public support for the campaign against Iran and Trump’s own pre-election promises to avoid involving the United States in new conflicts in the Middle East.

A Reuters/Ipsos poll published on Tuesday showed that 35 percent of Americans support strikes on Iran, down from 37 percent in a poll conducted last week.

Sixty-one percent expressed opposition to the attacks, compared with 59 percent last week.