Americans are being warned about the threat of terrorist attacks, demonstrations and violent actions following the killing of al-Qaida leader Ayman al-Zawahiri.
He was killed in a U.S. operation in Afghanistan on July 31.
The State Department issued a Worldwide Cautions notice on Tuesday.
"Current information suggests that terrorist organizations continue to plan terrorist attacks against U.S. interests in multiple regions across the globe," the State Department said.
U.S. officials warn the attacks could come in the form of suicide operations, kidnappings, hijackings, bombings and assassinations.
Americans traveling abroad are encouraged to check for travel advisories and maintain contact with the nearest U.S. Embassy or Consulate.