The deployment would mark a significant boost to Washington's military presence in the region, despite US President Donald Trump insisting that Tehran was taking part in peace talks with Washington to end the war.

The Wall Street Journal reported that the move would aim to provide Trump with "more military options" in the Middle East, engulfed by war since US-Israeli strikes on Iran on February 28.

The troops would join thousands of paratroopers and Marines who have already been ordered to the region.

An Iranian official said Wednesday that Tehran would retaliate to a ground invasion of its territory by Washington by activating its Houthi rebels in Yemen to attack shipping in the Red Sea.

That would open up a new front in a war of spiralling economic, political and military repercussions.

Trump has repeatedly said he does not plan to send ground troops into combat with Iran.

"It is unclear where precisely forces will go in the Middle East, but they will likely be within striking distance of Iran and Kharg Island, a crucial oil export hub off Iran's coast," the Journal said.

The Pentagon did not immediately respond to AFP's request for comment.

Trump has pushed back his deadline for strikes on Iran's energy assets, assuring that talks on ending the war were "going very well."

Israel's military, meanwhile, said early Friday that it carried out "a wide-scale wave of strikes targeting infrastructure of the Iranian terror regime in the heart of Tehran".