There have already been confrontations between the US military and Iranian forces. The US this month shot down a Shahed drone that approached the Abraham Lincoln carrier. On the same day, members of Iran’s Islamic Revolutionary Guard Corps threatened to board and seize a US-flagged tanker, prompting a US destroyer to respond.

Iran and the United States are waging gunboat diplomacy as talks over Tehran’s nuclear program hang in the balance.

Trump has warned Tehran it has days to reach a deal on its nuclear programme as the US continues massing forces, Iran drills with Russia, and Europe fears an imminent regional war. View on euronews

President Donald Trump on Thursday was considering a range of options for military strikes against Iran, including a possible limited strike aimed at enhancing the United States' negotiating position, a person familiar with the planning told ABC News.

As the United States continues a significant military buildup in the Middle East, Iran has taken steps to signal its readiness for war, including fortifying its nuclear sites and rebuilding missile production facilities.

WASHINGTON, Feb 19 (Reuters) - Iran told U.N. Secretary-General Antonio Guterres on Thursday that Tehran will consider bases, facilities and assets of the "hostile force" in the region as legitimate targets if it faces military aggression.

As Trump pressures Iran, he's spoken of an "armada" heading for the Mideast, but there's another massive movement of American fire power in the air.

Fox News @ Night’ panelists discuss the United States increasing its military presence in the Middle East as tension with Iran escalates.