The US military is redeploying aircraft and other forces in the Horn of Africa to prepare for possible further evacuations of Americans from South Sudan, the Pentagon said Monday.
"The secretary of defense has been following this situation very closely," spokesman Colonel Steven Warren told reporters.
"We are repositioning our forces in the area of concern," Warren added, saying units were readying in case the government orders more evacuations of Americans still on the ground, .
Apart from flying out foreign nationals, no other military action was under consideration, he said.
About 100 Americans were evacuated by US forces on Sunday after a previous attempt on Saturday had to be called off when American aircraft came under fire, with four troops wounded.
About 30 Americans remain at the US embassy in Juba, where "non-emergency" staff were already flown out in recent days.
The Pentagon was looking to move cargo planes and helicopters to a US base in Djibouti, as well as special 500-strong US Marine unit, a defense official told AFP on condition of anonymity.
The military has already sent in a 47-member joint task force to Juba to reinforce security at the US embassy.
President Barack Obama has warned South Sudan that any military coup would mean an end to diplomatic and economic support from the United States and its allies.