A method for determining an optimized trajectory to be followed by an aircraft, the method being implemented by a determining system of the aircraft and comprising: a first step for acquiring at least one constraint relative to at least one parameter of the trajectory to be followed, the constraint being determined by a control system of a remote station as a function of the air traffic and/or the aircraft mission; a step for calculating a desired trajectory as a function of the constraint; a step for transmitting the desired trajectory to the remote station; a second step for acquiring an instruction comprising an authorization to follow the desired trajectory or a refusal of the desired trajectory.