Nigerian officials in December declared a state of emergency in parts of the country because of violence attributed to Boko Haram. More than 100 members of the sect were arrested following a January attack on eight government sites in Kano in northern Nigeria.
The U.S. Embassy in Nigeria said it had information to suggest Boko Haram may be planning attacks in Abuja.
"The U.S. government has no additional information regarding the timing of these possible attacks," the warning stated.
During Easter weekend, the BBC reported Boko Haram may be planning coordinated attacks on Nigeria during the Christian celebration.
Boko Haram seeks to establish an Islamic state in Nigeria, a country divided largely along Muslim and Christian lines.
"The Nigerian government is aware of the threat and is actively implementing security measures," the embassy statement read.