Two Federal Maritime Commission commissioners said the Trump administration has begun enforcing measures to close a decades-old loophole that allowed cargo routed through Canadian and Mexican ports to avoid US Harbor Maintenance Tax fees, reported Ventura, California's gCaptain.

Commissioners Max Vekich and Laura DiBella said the move marks a significant shift in maritime trade enforcement, targeting distortions in cargo flows and port competition. They commended the administration for addressing what they called a threat to the US economy and maritime interests.

The action follows Section 6 of President Trump's April 2025 executive order, Restoring America's Maritime Dominance, which directed Homeland Security and Customs to enforce collection of duties, taxes and fees, including the Harbor Maintenance Tax, on foreign cargo entering via land borders. A new 10 per cent service fee will cover additional processing costs.

The Harbor Maintenance Tax, set at 0.125 per cent of cargo value, funds US port upkeep. For nearly two decades, shippers have avoided it by routing cargo through Canadian and Mexican ports, reshaping North American trade flows. Canadian ports, backed by government investment, expanded capacity to capture US-bound cargo.

A 2012 FMC study estimated that eliminating the disparity could shift half of US-bound container traffic from Canada's West Coast back to American gateways. Similar competitive pressures have grown from Mexican ports as cross-border logistics expanded.

The commissioners warned that inaction risked further loss of US port traffic, investment and jobs, with Canadian and Mexican terminal projects threatening closures at American ports. They said closing the loophole would benefit US workers and strengthen domestic port competitiveness.

The White House described the policy as a fairness measure to level the playing field for US ports. The commissioners noted their comments reflected personal views, not necessarily the official position of the FMC.