The US embassy in Mozambique said on Friday it had "information pointing to the likelihood of imminent attacks" in the country's north, which has recently been rocked by attacks blamed on jihadists.
"We strongly advise American citizens in the district headquarters of Palma to consider departing the area immediately," said an advisory posted on the embassy's website.
Palma, in Mozambique's northern Cabo Delgado province, is expected to become an energy hub after promising discoveries of natural gas.
But the region has seen a string of assaults on security forces and civilians since October.
Almost 30 people have been killed in machete and knife attacks in rural areas that police have linked to an unnamed jihadist group.
The US statement said that American citizens "who elect to remain in Palma district are strongly advised to avoid travel to the district headquarters".
It also encouraged them to "postpone visits to both government offices and retail locations, including markets".
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