Zelaya was bundled out of office and into exile in Costa Rica in a military coup on Sunday. There has been a tide of international condemnation for the ouster, from U.S. President Barack Obama to the Honduran leader's leftist allies in Latin America, led by Venezuela's Hugo Chavez.
In Honduras, pro-Zelaya protesters have clashed in the streets with security forces.
Zelaya said on Monday evening he planned to return to Honduras on Thursday, accompanied by OAS chief Jose Miguel Insulza. The news that Argentina's President Cristina Fernandez also planned to travel with him added to the pressure on the interim leaders of Honduras to back down.