The U.S. Embassy in Baghdad has issued a security alert to U.S. citizens that warns of "heightened tensions" in Iraq and advises against travel to the country.
The advisory warning was issued late on May 12 amid rising tensions between neighboring Iran and the United States.
The U.S. Embassy did not give details about the nature of the threats.
Last week, U.S. Secretary of State Mike Pompeo paid an unexpected visit to Baghdad where he met with Iraqi officials to discuss U.S. security concerns amid what he called "escalating" Iranian activity.
His visit came after Washington announced the deployment of an aircraft carrier battle group and a bomber task force to the Middle East, which a U.S. official said was in response to threats from Iran to U.S. interests or its allies in the region.
"In the event that Iran decided to come after an American interest -- whether that be in Iraq or Afghanistan or Yemen or any place in the Middle East -- we are prepared to respond in an appropriate way," Pompeo told CNBC in an interview to be broadcast on May 13.
"Our aim is not war," Pompeo added.