If either of the Contracting Parties considers it desirable to modify any provision of the present Agreement, it may request consultation with the other Contracting Party in accordance with Article 14. Such consultations, which may be between Aeronautical Authorities and which may be through discussion or by correspondence, shall begin within a period of sixty (60) days from the date of the request unless both Contracting Parties agree to an extension of this period. Any modification so agreed shall come into force when they have been confirmed by an exchange of diplomatic notes. Modifications of the Annex shall be made by direct agreement between the Aeronautical Authorities of the Contracting Parties. Such modifications would be effective from the date of the approval of the Aeronautical Authorities.