President Trump has not authorized military action in Iran, but the U.S. has built up its presence in the region in recent days.

The U.S. has ordered some of its military personnel to depart from bases in the Middle East on Tuesday as tensions with Iran escalate.

Congress is backing increases to the size of the military, having passed and proposed final legislation that will raise and fund rises in end strength.

The United States and Iran appear to be moving closer to military conflict, with President Donald Trump saying Washington is "ready, willing, and able" to strike its arch-foe, and Tehran vowing a "crushing response.

The US has ramped up diplomatic moves, including sanctions on Iranian officials.

While few details of the exact work at Pituffik have been made public, the improvements come during a time of intense focus on Greenland.

Mexico is showing sensitivity to U.S. military movements since the attack earlier this month on Venezuela. On Friday, the U.S.

Greenland's natural resources and proximity to Russia and China have made it a valuable strategic asset to the US military since World War II.

Allies and partners are now pushed not only to align strategically and spend more on their own security, but also to accept the economic and political terms of “America First.”

Trump says US ‘armada’ is heading towards the Gulf, raising fears of a military escalation in the region.