Chad's military junta took charge on April 20 after President Idriss Deby Itno, Chad's 30-year leader, died fighting rebels.

Deby's son Mahamat, a four-star general, declared himself president after the death of his father, who had ruled Chad with an iron fist for three decades.

In Brazzaville on Friday the presidents of Angola, the Central African Republic, Congo and the Democratic Republic of Congo urged the junta leaders to organise "an inclusive national dialogue as soon as possible".

In their final statement after the Economic Community of Central African States (CEEAC) meeting, they called for all political actors "to achieve the objective of political transition within 18 months".

The wider African Union last month called for the same transition in the same time-scale.

"We take note of the suspension of Chad's 2018 constitution and the putting in place of a transitional military council," said the CEEAC statement, which was read out by Congo-Brazzaville's Foreign Minister Jean-Claude Gakosso.

The Central African leaders encouraged Chad's bilateral and multinational financial partners to support the country.

Along with the heads of state gathered in Brazzaville, Equatorial Guinea and Burundi were represented by their vice presidents, while the Chadian and Gabonese prime ministers also attended.

"Chad's transition needs the support of everyone," said African Union commission chair Moussa Faki Mahamat, himself a former Chad prime minister, as he opened the summit.

Congo's veteran President Denis Sassou Nguesso, hosting the meeting, said that "Our duty and our responsibility... lead us to an even stronger commitment in the service of a peaceful transition in Chad".