A system for supplying ventilatory support may include a nasal interface configured to communicate with a patient's nose while allowing the patient to breathe ambient air directly without flowing through the nasal interface. A nozzle may be associated with the nasal interface at a distance from a nose. The nozzle may be connectable to the gas delivery circuit and the gas delivery source. The nozzle may be capable of delivering gas into the nasal passage by creating negative pressure area near the nozzle and a positive pressure area near the entrance to the nose. A combination of gas from the gas delivery source and air entrained from the gas exiting the nozzle may provide ventilatory support.