The West African regional body Ecowas has suspended Mali after last week's military coup.
A delegation of several Ecowas heads of state is to go to Mali to press the coup leaders to restore democracy.
Meanwhile, the coup leaders announced that a curfew imposed when they seized power last Wednesday would be lifted.
The coup was led by soldiers unhappy with the way President Amadou Toumani Toure's government had been handling a Tuareg insurgency in northern Mali.
The decision to suspend Mali was taken at an emergency meeting of Ecowas held in the Ivorian capital Abidjan.
"The security and political situation [in Mali]... dangerously threatens not only the peace and security in Mali but also the peace, stability and development of all the member countries of Ecowas," Kadre Desire Ouedraogo, head of Ecowas's commission, told the Associated Press.
"We cannot allow this country endowed with such precious democratic instruments, dating back at least two decades, to leave history by regressing," said Ivory Coast President Alassane Ouattara, who also currently heads Ecowas.
The African Union had also described the coup as a "significant setback" for the country, and the move has attracted widespread international condemnation.
Mr Ouattara is expected to be in the Ecowas delegation to Mali, along with the heads of state of neighbouring Benin, Burkina Faso, Niger and Liberia.
Mr Toure's whereabouts are still unknown after mutineers stormed the presidential palace last week.
However, the French foreign ministry confirmed on Tuesday that its ambassador in Mali had been in contact with Mr Toure and that he had given reassurances that he was safe.