The Legal Affairs and External Relations Bureau (LEB) undertakes the international air law programme with a view to strengthening the international legal framework to address current and emerging civil aviation challenges effectively through the Chicago Convention, its Annexes and other air law instruments. LEB further provides advice and assistance on legal and external relations matters generally and in support of other Strategic Goals and Enablers of ICAO and develops and implements the communications programme. 

Pursuant to the ICAO Strategic Goal of International Civil Aviation Convention, other Treaties, Laws and Regulations Address All Challenges, LEB carries out two projects under the international air law programme: (i) promoting widespread ratification and implementation of international air law instruments, and (ii) facilitating the development of international air law instruments and guidance material in response to emerging challenges and opportunities. The Director of LEB serves as Secretary to the Legal Committee and LEB also supports various working groups, task forces and study groups in conducting research and study of subjects of international law, in particular, international air law. LEB provides comprehensive Secretariat support for the administration of the settlement of differences pursuant to Chapter XVIII of the Chicago Convention.

In supporting other Strategic Goals and Enablers of ICAO, LEB provides legal advice and opinions to the ICAO Member States, Governing Bodies, President of the Council and the Secretary General, and other ICAO Bureaus and Regional Offices on any issue of law, and in particular on international law and air law;  reviews all agreements and contracts; participates in the system of administration of justice; and performs the treaty depositary and aeronautical arrangements registration functions of the Organization. 

With regard to external relations matters, LEB is responsible for maintaining close and harmonious working relations with Member States; serving as focal point for the Organization’s relations with the Host Government; carrying out liaison and protocol functions; and monitoring and providing policy guidance and advice on current political events which might affect ICAO. 

In terms of communications, LEB develops and implements a comprehensive communications programme and acts as the principal point of contact for all media-related activities.