The Secretary may provide special monetary incentives to acquire or retain proficiency in foreign languages to civil service employees who serve in domestic positions requiring critical language skills that are located in the 50 United States, the District of Columbia, and non-foreign areas (the Commonwealth of Puerto Rico, the Commonwealth of the Northern Mariana Islands, and other United States territories and possessions). The amounts of such incentives should be similar to the language incentive pay provided to members of the Foreign Service pursuant to section 4024(b)(3) of this title, as amended by section 5206.