KHARTOUM, July 18 (Xinhua) -- The talks scheduled for Friday between Sudan's Transitional Military Council (TMC) and the opposition Freedom and Change Alliance were postponed, the opposition alliance said in a statement on Thursday.

"It has been agreed to delay the meeting regarding the constitutional declaration indefinitely," Munzir Abul-Mali, a leading member in the alliance, said in a statement without giving reasons for the delay.

On Wednesday, the TMC and the alliance signed with initials on the political declaration, a step towards consensus and institution for the transitional period structures.

However, the two sides agreed to postpone the signing of the constitutional declaration, which determines the powers of the transitional period structures.

The signed declaration was reached under the joint mediation of the African Union and Ethiopia.

It stipulates establishment of a joint sovereignty council of 11 members, including five civilians and five military representatives, in addition to one civilian to be selected through consultation between the two sides.