3. Amendments to this Agreement shall enter into force for the Parties ratifying, approving or accepting them on the thirtieth day following the deposit of instruments of ratification, approval or acceptance by two thirds of the number of Parties to this Agreement as at the time of adoption of the amendment. Thereafter, for each Party depositing its instrument of ratification, approval or acceptance of an amendment after the deposit of the required number of such instruments, the amendment shall enter into force on the thirtieth day following the deposit of its instrument of ratification, approval or acceptance.