The US has reached agreement with Iceland on how to end its military presence in the country.
The base used to have F-15s, helicopters and sub-hunting aircraft
The US Navy is due to leave the island by the end of this month, ending a military presence dating back to 1951.
The Keflavik naval and air base played a key role in the Cold War, monitoring Soviet submarines and housing aircraft that could be sent to destroy them.
The US says that a new era - in which it is fighting a "war on terror" - means Keflavik is no longer needed.
The Pentagon has now agreed the final details of the base's closure, which has been under way since March.
As Iceland has no army of its own, it will become one of the few countries with no military presence at all.
The US says it will not be left unprotected, however.
A spokesman insisted the pull-out would not affect the US commitment to defend Iceland as a Nato ally.
"In the height of the Cold War, this was the place to be to protect against Soviet submarines. And we were successful and the [Keflavik] team had a great deal to do with that," said Rear Adm Noel Preston, the navy's European region commander, in a ceremony earlier this month.
"Now the world has changed, and we are facing a war on terrorism. We are changing how we plan and prepare for this war. But what will not change is our friendship and partnership with Iceland."