The African Union on Friday suspended Madagascar from the continental body, saying the replacement of the island nation's president by an army-backed politician constitutes a coup.

The union's decision follows the declaration a day earlier by Southern African nations that they will not recognize Madagascar's new leader, Andry Rajoelina.

The Southern African Development Community also urged the AU and the international community not to recognize Rajoelina as president and called for a return to "democratic and constitutional rule in the shortest time possible."

The AU's second most important body, the Peace and Security Council, has given Madagascar six months to restore a constitutional government, probably through elections, said Bruno Nongoma Zidouemba, the council's temporary chairman.

If it does not comply, the AU will consider imposing sanctions on the Indian Ocean island's leaders, Zidouemba told reporters.

"The council is of the opinion that what's occurred in Madagascar entered into the definition of an unconstitutional change of government," said Zidouemba, Burkina Faso's ambassador to the AU.

He said the AU had also asked foreign governments, including France, which has supported the new president, to stand by the AU's position.

On Thursday, the United States also said it would reconsider aid to the island nation.

When asked if the AU would still permit Madagascar to host the AU summit in June or July, an AU commission official was vague.

"I cannot speculate at this point in time," said Geofrey Mugumya, the peace and security department director. "But anything could happen."

After months of street protests, Marc Ravalomanana resigned as Madagascar's president Tuesday and placed power in the hands of the military. Within hours, the military announced it was making opposition leader Rajoelina the country's new president.

Rajoelina has accused his ousted rival of misspending public funds and undermining democracy. He says his rise was a victory for "true democracy" over dictatorship and has promised new elections within two years.

France, Madagascar's former colonial power and biggest donor, said two years was too long to wait for elections.

Ravalomanana had accused Rajoelina of seeking power by unconstitutional means, since under the constitution the 34-year-old opposition leader was too young to become president.