49 U.S.C. § 44906

The Administrator of the Transportation Security Administration shall continue in effect the requirement of section 129.25 of title 14, Code of Federal Regulations, that a foreign air carrier must adopt and use a security program approved by the Administrator. The Administrator shall not approve a security program of a foreign air carrier under section 129.25, or any successor regulation, unless the security program requires the foreign air carrier in its operations to and from airports in the United States to adhere to the identical security measures that the Administrator requires air carriers serving the same airports to adhere to. The foregoing requirement shall not be interpreted to limit the ability of the Administrator to impose additional security measures on a foreign air carrier or an air carrier when the Administrator determines that a specific threat warrants such additional measures. The Administrator shall prescribe regulations to carry out this section.