The United States today revealed tightening measures related to steel and aluminum imports from Mexico, as part of its efforts to prevent Chinese-origin goods from evading duties.

This is the latest step taken by President Joe Biden’s administration in the period leading up to the elections, as part of a series of efforts aimed at protecting against excess industrial capacity in China, which Washington has often warned could lead to the flow of goods at unfair prices to other markets.

Steel imported from Mexico will not benefit from customs exemption unless it is smelted and cast in the aforementioned country or in the United States or Canada, according to White House economic advisor Lael Brainard. Otherwise, it will be subject to a 25% fee.

Under Biden’s latest announcement, aluminum imports from Mexico that contain primary aluminum smelting or are cast in China, Belarus, Iran or Russia will be subject to a 10% duty.

Mexico will require importers to provide information on the countries of origin of the products.

These measures fill a major loophole that the previous administration failed to address, and countries such as China use them to avoid US customs duties by shipping their products through Mexico, according to Brainard.

She said: “Chinese steel and aluminum entering the US market through Mexico avoids tariffs, undermines our investments and harms American workers in states such as Pennsylvania and Ohio.”

As Biden’s attempt to win a second term enters a critical stage, the president is working to gain the support of voters in swing states, including Pennsylvania.