A website used by Islamist militants had published the threats, the US embassy said in a memo sent to US citizens living in the country, Xinhua reported citing the United Arab Emirates (UAE) daily The National.
According to the report, the government of the UAE, a long-term US ally in the Middle East, promises full support in keeping American institutions secure and in verifying the threats, although it added no specific threats had surfaced.
The memo has triggered an avalanche of phone calls made by concerned parents at American and international schools.
The embassy asked its citizens to remain vigilant and keep mobile phones stored with emergency numbers.
There are seven American schools in the UAE, located in Abu Dhabi, Dubai and Sharjah. There is no official number of US citizens in the UAE, but according to different media reports, there are approximately 40,000 US citizens living in the UAE, many of them with dual nationality or another passport from an Arab or Asian country.