Cristina Kirchner, Argentina's president, has been among the staunchest defenders of Zelaya's right to return to power.
Argentina is among six member nations from the Organisation of American States (OAS), due to send their foreign ministers to Honduras to pressure the interim administration to enter into fresh talks with Zelaya.
No date has been fixed for the foreign ministers to visit members of the interim government, which insists that its sacking of Zelaya is supported by the country's congress, supreme courts and the military.
Last week, a visit to Tegucigalpa by an OAS delegation was postponed after the interim government said it wanted Jose Miguel Insulza, the head of the regional organisation, to stay away.
The expulsion of the Argentinian diplomats comes days after Micheletti's government told Venezuelan envoys to leave Honduras.
Those diplomats have refused the order, saying that to do so would constitute recognition of the de facto government.
Officials from the US state department are planning to receive a delegation representing the Honduran interim government in Washington, Ian Kelly, a spokesman for the department said.
The US officials will meet the delegation at the headquarters of the OAS to work "toward restoration of democratic and constitutional power in Honduras", Kelly said on Tuesday.
But the meeting "in no way is meant to imply any kind of acceptance of the de facto regime in Tegucigalpa", he said.
The US government has suspended millions of dollars in aid to Honduras as part of efforts to prompt the reinstatement of Zelaya, who was forced from power after he pushed for a referendum on constitutional changes.
Micheletti's supporters say that the referendum was part of a move by Zelaya to extend his rule beyond a single presidential term, while the ousted leader has said that he was trying to improve living standards for the poor.