The United States could establish new military facilities at Mestersvig in eastern Greenland and Narsarsuaq in the south under a defense agreement signed this week with Denmark, potentially expanding the American military presence on the Arctic island for the first time in decades.

Mestersvig is particularly significant because of its location near the GIUK gap, the strategic stretch of ocean between Greenland, Iceland and Britain that Russian naval forces would have to cross to reach the North Atlantic. NATO considers the corridor important for monitoring and limiting Russian naval activity.

The remote Mestersvig facility currently has only three Danish soldiers stationed there. Built in the 1960s, it includes barracks capable of housing roughly 150 troops and an airstrip about 1.1 miles long that can accommodate military transport aircraft.

The United States has not publicly detailed its plans for the site. The facility sits roughly 149 miles from the nearest settlement and inside a vast national park where winter temperatures average around 14 degrees Fahrenheit.

The location has a long military history. During World War II, Greenland became part of the Allied and German struggle to monitor Arctic weather, which could influence conditions across the North Atlantic and Europe. German forces established secret weather stations in the region before Danish patrols and Allied forces drove them out.

The area could also become more important economically. An EU-backed project is seeking to develop a molybdenum mine about 12 miles from Mestersvig, while a Texas-based oil company plans to explore an untested basin south of the facility this winter, though it has not yet received the necessary permit.

Local officials have welcomed the potential investment and infrastructure improvements that could accompany an expanded military presence.

Mestersvig's harsh environment remains a major challenge. The airstrip can receive as much as 5 meters of snow annually, requiring constant maintenance during storms and making the remote outpost one of the most difficult places for personnel to operate.

The agreement comes as the Arctic becomes increasingly important to U.S. and NATO defense planning, with Greenland's location providing access to the North Atlantic and Arctic approaches.