The U.S.-Mexico-Canada Agreement will face tougher challenges in Congress if the Trump administration includes language in implementing legislation that would make it more expensive to import goods valued at $800 or less, industry sources said.

The provision would increase the difficulties of passing the agreement “where there are already plenty” of problems, one industry source told Bloomberg Law. For some companies, this is their No. 1 issue, she said.

The administration and the Senate Finance and House Ways and Means committees are in consultations to prepare legislation to implement the USMCA.

“Our concern is that the administration may seek to...