Under such terms and conditions as he shall determine and consonant with the purposes of this section, the President is authorized to extend, or to enter into an agreement extending, to the Mission to the United States of America of the Commission of the European Communities, and to members thereof, the same privileges and immunities subject to corresponding conditions and obligations as are enjoyed by diplomatic missions accredited to the United States and by members thereof. Under such terms and conditions as the President may determine, the President is authorized to extend to other offices of the Commission of the European Communities which are established in the United States, and to members thereof—