The US says it has ordered families of defence personnel and diplomats out of parts of Turkey amid security fears.
Dependants are being moved out of Adana, Izmir and Mugla provinces.
The US European Command said the decision was not permanent but “intended to mitigate the risk to [Department of Defense] elements and personnel, including family members”.
Once a beacon of stability, Turkey has entered a period of high tension and violence.
Key cities have been struck by a spate of deadly bombings. Meanwhile Turkey has been fighting Kurdish militants in its restive east and struggling to prevent violence spreading from across its border with Syria.
The US State Department has warned all Americans against travel to south-eastern Turkey.
Pentagon spokesman Peter Cook said the decision had been made out of an “abundance of caution”.
“There’s no specific threat that triggered this but a broader decision based on what we’ve seen in the region,” he said.
Turkish President Recep Tayyip Erdogan is visiting the US this week to attend President Barack Obama’s nuclear security summit.
But rarely have relations between the US and one of its key Nato allies been so poor as those between Washington and Ankara, says the BBC’s diplomatic correspondent Jonathan Marcus – with each other’s response to the Syrian crisis a particular point of friction.
Some 5,000 US service personnel and dependants are based at the Incirlik air base in the southern city of Adana – from which the US launches air strikes on fighters from so-called Islamic State in Syria and Iraq.
But security fears last July prompted officials to ban troops and their families from frequenting the “American alley” of markets and kebab restaurants which had flourished outside the base’s gates.
Two months later, officials offered military families the chance to evacuate voluntarily – an option only few took up. Now they are being involuntarily evacuated.
“This decision allows for the deliberate, safe return of family members from these areas due to continued security concerns in the region,” said the US European Command statement.
The state department, meanwhile, said it had also ordered the departure of family members of employees at the US Consulate in Adana as well as family members of US government civilian employees in the western Izmir and Mugla provinces.
In a statement, it warned US citizens of “increased threats from terrorist groups throughout Turkey and to avoid travel to south-eastern Turkey”.
The decision to evacuate was made in consultation with the Turkish government, said the European Command.
“We understand this is disruptive to our military families, but we must keep them safe and ensure the combat effectiveness of our forces to support our strong ally Turkey in the fight against terrorism.”
The battle against militants from so-called Islamic State remained a priority for both Turkey and the US, it said.