The deposed president of Honduras, Manuel Zelaya, will be accompanied by the presidents of Argentina and Ecuador for his planned return on Thursday.
The secretary-general of the Organisation of American States, Jose Miguel Insulza and the UN General Assembly president, Miguel D'Escoto will also accompany him.
Mr Zelaya was flown to Costa Rica on Sunday by the Honduran military.
He was expelled after trying to change the constitution to let presidents seek re-election beyond a single four-year term - a move opposed by Congress, the courts and the army.
He is now in New York, where he has received the backing of the United Nations General Assembly. However, General Assembly resolutions are not legally binding.
Mr Zelaya said he intended to finish his current mandate, ending in January, and would not run for office again. He took office in 2006.
Interim foreign minister Enrique Ortez said on Tuesday Mr Zelaya would be arrested if he returns to Honduras.