Major General Michael Turello, commander of the US Combined Joint Task Force-Horn of Africa mission, said in a statement the "precautionary measure" gives him more powers to deal with a COVID-19 outbreak.

"Combating COVID-19 is my top priority," Turello said.

"By declaring a public health emergency, it keeps our forces, and those of our host nation partner, as healthy and as safe as possible."

The statement did not say whether there were any infections among US military and civilian personnel in Djibouti.

US forces operate out of two installations, Camp Lemonnier Djibouti and Chabelley Airfield, and in the local port.

Djibouti, a busy shipping hub strategically located at the southern entrance to the Red Sea, has reported 985 cases of coronavirus, up more than 400 from a week ago.

As of Thursday, the US Department of Defense has counted 5,901 coronavirus cases worldwide among military and civilian personnel and their families, with 25 deaths.