Dozens of fighter jets, including F-35s, F-22s, F-15s and F-16s, left bases in the U.S. and Europe and were spotted heading to the Middle East by the Military Air Tracking Alliance, a team of about 30 open-source analysts that routinely analyzes military and government flight activity.

A look at the warships, jet fighters and missiles massing at Iran’s doorstep.

Iran-US Tensions LIVE: With Donald Trump pressing Tehran to strike a nuclear deal, Iran’s atomic energy chief Mohammad Eslami said on Thursday that no country can strip the Islamic Republic of its right to nuclear enrichment.

Washington has increased its military presence in the Middle East and is preparing contingency plans for possible action against Tehran, which has warned for a regional war in case of an attack from the US or its allies.

A second American aircraft carrier -- the USS Gerald R. Ford -- is heading toward the Middle East amid rising tensions with Iran, accompanied by destroyers and aircraft being redeployed from missions in the Caribbean region, a U.S. official told ABC News.

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.

Iran held annual military drills with Russia on Thursday as a second American aircraft carrier drew closer to the Middle East, with both the United States and Iran signaling they are prepared for war if talks on Tehran's nuclear program fizzle out.

Ayatollah issues warning as nuclear talks under way – but president says Tehran will never abandon its enriched uranium programme