The US consulate in the Gulf Arab emirate of Dubai reopened on Thursday after closing to the public for security reasons on Wednesday, it said without giving details of any threats.
The United States reminded citizens in June to remain vigilant to the threat of attacks after Britain raised its threat alert for the United Arab Emirates.
The United States last updated its warden message in July, issuing a worldwide caution to American citizens about the "continuing threat of terrorist actions and violence against Americans and interests throughout the world".
Several Gulf countries have faced attacks from Islamist militants angry over their close ties with the West, but there has been no major attack or political unrest in the UAE, a federation of seven emirates that includes Dubai.