Several countries are evacuating their citizens from South Sudan following days of fighting that saw hundreds of people killed.
Germany, the UK, Italy, Japan, India and Uganda have already started taking their citizens out of the country.
A ceasefire between forces loyal to President Salva Kiir and Vice-President Riek Machar is holding for a second day in the capital, Juba.
Mr Machar and his troops have also left Juba “to avoid further confrontation”.
The evacuations are being carried out by military and chartered planes, as commercial flights have not yet resumed.
However, Kenyan Foreign Minister Amina Mohammed has told the BBC that Kenyan nationals would not be evacuated, as the ceasefire in South Sudan was holding.
The US embassy in Juba said it was organising flights to evacuate non-essential staff and all US citizens wishing to leave.
President Barack Obama later announced 47 troops were being sent to protect the US embassy and its staff.
He added that 130 more personnel were being sent to Djibouti to stand ready for deployment if necessary.
Germany’s foreign ministry said its air force was evacuating other European nationals, as well as its own citizens.
During the fighting, Mr Machar’s base in Juba was overrun.
Mr Machar’s spokesman James Gatdet Dak told the BBC that the vice-president was now near the capital but refused to be more specific.
He called for an international buffer force to be deployed to avoid “further confrontation” and ensure that the ceasefire holds.