Move by State Department and Pentagon comes as Turkish leader Recep Tayyip Erdogan is set to arrive in Washington.
Family members of US consulate staff in Istanbul have been asked to leave the country, the US state department said, citing threats against US citizens.
“The Department of State made this decision based on security information indicating extremist groups are continuing aggressive efforts to attack US citizens in areas of Istanbul where they reside or frequent,” the department said in a statement on Sunday.
The US Consulate General in Istanbul will stay open, the state department said, adding that the order does not apply to any other US diplomatic posts in Turkey.
Saturday’s warning updates previous state department advisories of “increased threats from terrorist groups throughout Turkey”.
The department also advised its citizens to avoid travel to southeast Turkey and cautioned on the risks of travelling anywhere in the country.
France temporarily shut down its embassy in the Turkish capital Ankara and its consulate in Istanbul nearly two weeks after Istanbul’s main airport was attacked in an assault that killed 47 people.
Some of the violence in neighbouring Syria has spilled over to Turkey, which has seen a rise in attacks this year. The security situation has further deteriorated in the wake of a a failed coup attempt in July.