The US embassy in the Turkish capital Ankara will be closed to the public on Monday over a “security threat”, the mission announced on its website.
The embassy was the target in 2013 of a suicide bombing claimed by a far-left group that killed a Turkish security guard.
Relations between NATO allies Washington and Ankara are strained over a number of issues, notably the US arming of a Syrian Kurdish militia, the Syrian Kurdish People’s Protection Units (YPG).
Ankara on January 20 launched an operation against the YPG in its border stronghold of Afrin in western Syria.
Turkey has called on Washington to stop working with the YPG, which it views as a “terrorist” group.
But the United States has expressed concern about the Turkish Operation dubbed “Olive Branch” and urged restraint from Turkey.