The Assembly, comprised of all Member States of ICAO, meets not less than once in three years and is convened by the Council at a suitable time and place. An extraordinary meeting of the Assembly may be held at any time upon the call of the Council or at the request of not less than one-fifth of the total number of Member States.
 
The Assembly has numerous powers and duties, among them to: elect the Member States to be represented on the Council; examine and take appropriate action on the reports of the Council and decide any matter reported to it by the Council; and approve the budgets of the Organization. The Assembly may refer, at its discretion, to the Council, to subsidiary commissions or to any other body any matter within its sphere of action. It can delegate to Council the powers and authority necessary or desirable for the discharge of the duties of ICAO and revoke and modify the delegations of authority at any time; and deal with any matter within the sphere of action of ICAO not specifically assigned to the Council. In general, it reviews in detail the work of the Organization in the technical, administrative, economic, legal and technical cooperation fields. It has the power to approve amendments to the Convention on International Civil Aviation (Chicago, 1944), which are subject to ratification by Member States.