The Economic Community of West African States (ECOWAS) suspended Guinea's membership in the bloc after a military coup this past weekend.
The move comes amid fears of deterioration of democracy in West African countries and drawing parallels with recent coups in Mali.
ECOWAS "has decided to suspend Guinea from all of its decision-making bodies," Burkina Faso's Foreign Minister Alpha Barry said after the leaders from the 15-member bloc discussed the crisis in a video summit.
Barry said the bloc called on the coup leaders to release detained President Alpha Conde.
The bloc urged Guinea "to put in place a process that will allow a rapid return to normal constitutional order."
ECOWAS is expected to send a mediation mission to Guinea's capital, Conakry, on Thursday.
The United Nations and African Union have also condemned the military coup.