President Trump has waived the Jones Act, a shipping law that allows only American-owned and operated ships to carry goods and passengers to and from U.S. ports, for Puerto Rico. Press Secretary Sarah Sanders made the announcement on Twitter. The act was waived for Texas and Florida after Harvey and Irma to open up ports for resources.

The backdrop: The Trump administration came under fire for initially denying Puerto Rico's request for a Jones Act waiver. Sen. John McCain tweeted that the refusal was "unacceptable." On Wednesday, Trump told reporters he was considering a waiver but "a lot of people that work in the shipping industry...don't want the Jones Act lifted."

Go deeper: A week after Maria, Puerto Rico still desperate for water and supplies