A career candidate for appointment as a Foreign Service officer may not be initially assigned under section 3964 of this title to a salary class higher than class 4 in the Foreign Service Schedule unless—

(1) the Secretary determines in an individual case that assignment to a higher salary class is warranted because of the qualifications (including foreign language competence) and experience of the candidate and the needs of the Service; or

(2) at the time such initial assignment is made, the candidate is serving under a career appointment in the Service and is receiving a salary at a rate equal to or higher than the minimum rate payable for class 4 in the Foreign Service Schedule.