"The embassy is aware of a general but uncorroborated threat against the Marriott hotel in Islamabad. US citizens are advised to avoid the area for the next several days to allow time to assess the situation," said an advisory posted on the website of the embassy here on Saturday.
Marriott hotel was bombed on September 20, 2008, which killed over 54 people and injured dozens others.
Several Americans were among the dead.
In the advisory, the embassy reminded US citizens there is an active travel warning for Pakistan which was issued on April 7, 2016 and a worldwide travel alert issued on November 23, 2015.
US citizens in Pakistan are strongly urged to avoid hotels that do not apply stringent security measures, it added.
The message pointed out that official US Mission personnel and visitors were not allowed to use public transportation and were not authorised to stay overnight in hotels in Pakistan.