The U.S. military is closing 15 bases and facilities throughout Europe, the Pentagon announced Thursday.
The cost of the closures is $1.4 billion, but the savings will be $500 million annually beginning in the early 2020s, said John Conger, acting assistant secretary of Defense for energy, installations and environment.
Facilities in the United Kingdom, Germany, Belgium, the Netherlands, Italy and Portugal will be closed between 2018 and 2021, with as many as 1,100 host nation jobs lost.
"The United States remains strongly committed to NATO and our forward presence of military forces in Europe," said Gen. Philip Breedlove, the NATO supreme allied commander, in a statement Thursday.
"At the same time, in the context of a challenging fiscal environment, we must seek greater efficiencies with respect to our presence in Europe and ensure we are focusing resources where they can have the greatest effect," he said.
The U.S. currently has 67,000 troops in Europe.
Lawmakers and some defense experts have criticized the Pentagon for downsizing the number of U.S. forces in Europe, given a resurgent threat from Russia.
However, the Pentagon said troops would be positioned to still allow the U.S. and NATO allies to respond quickly to crises worldwide.
"The adjustments and resulting efficiencies will help ensure the U.S. can maintain a persistent and capable presence in Europe," said Breedlove.
Derek Chollet, assistant secretary of Defense for international security affairs, said the savings would allow the U.S. to maintain its presence in Europe.
"Maintaining a strong robust presence in Europe is absolutely vital to our security interests," he said Thursday.
The White House's $985 million European Reassurance Initiative, approved by Congress in December, will support a rotational presence of U.S. troops for training, exercises and other NATO activities, the Pentagon said.
It will also support an increase of U.S. and NATO military presence in eastern Europe, pre-position U.S. equipment in Europe and go toward building the capacity of allies Ukraine, Georgia and Moldova.
The Pentagon also announced the first F-35 Joint Strike Fighters will be based at Royal Air Force Station Lakenheath in the United Kingdom.
The first aircraft are scheduled to arrive in 2020. Two squadrons will be permanently based there.
"The presence of U.S. F-35s at Lakenheath will deepen our already close partnership and offer new opportunities for collaboration between the U.S. and the U.K.," the Pentagon said in a statement.
The removal of about 3,200 U.S. personnel from Royal Air Force Station Mildenhall will be offset by the addition of about 1,200 U.S. troops that will be permanently stationed with the two F-35 squadrons.
Various U.S. units will rotate through Germany during the next several years, with an anticipated increase of several hundred troops.
The Pentagon will also add 300 troops to Italy when the 606th Air Control Squadron from Spangdahlem Air Base, Germany, is relocated there.
There will be a decrease of about 500 troops and civilians from Portugal from Lajes Field in the Azores.
The first round of base and facilities closures in Europe was announced last May in a move to save $60 million annually.
—This report was updated at 11:00 a.m.