; (B) the length of the period of service required to be completed before such agent is entitled to retain such payment; and (C) any other terms and conditions to which such payment is subject. (b) Retention bonuses Subject to the approval of the Secretary of Homeland Security, the Commissioner of U.S. Customs and Border Protection may pay annual retention bonuses, not to exceed 15 percent of the agent's basic pay, to U.S. Border Patrol agents after the completion of each year of satisfactory service, as determined by the Commissioner. (c) Relocation bonus Subject to the approval of the Secretary of Homeland Security, the Commissioner of U.S. Customs and Border Protection may pay a relocation bonus, not to exceed 15 percent of the agent's annual basic pay, to a U.S. Customs and Border Protection agent who agrees to be transferred and to serve for not less than 3 years at the new duty station. (d) Limitation None of the bonuses paid to a U.S. Customs and Border Protection agent pursuant to subsections (a) through (c) may be considered part of the basic pay of such agent for any purpose, including for retirement or in computing a lump-sum payment to the agent for accumulated and accrued annual leave under section 5551 or 5552 of title 5, United States Code. 6. Treatment of aliens arriving from contiguous territory Section 235(b)(2)(C) of the Immigration and Nationality Act ( 8 U.S.C. 1225(b)(2)(C) ) is amended by striking may return and all that follows and inserting the following: shall— (i) return the alien to such territory, or to a safe third country (as described in section 208), pending the completion of a proceeding under section 240; or (ii) detain the alien for further consideration of an application for asylum, which shall include a determination of credible fear of persecution. .