The U.S. is challenging tariffs imposed on some U.S. exports by China, the EU, Canada, Mexico and Turkey. The U.S. launched the separate disputes at the World Trade Organization on Monday.
U.S. Trade Representative Robert Lighthizer said in a statement that the tariffs are unjustified "under international rules" and "appear to breach each WTO Member's commitments under the WTO Agreement."
The move comes after President Donald Trump imposed tariffs on steel and aluminum imports.
China, the EU, Mexico, Turkey and Canada responded with tariffs on a combined $28.5 billion worth of U.S. exports.
Lighthizer's office has said that Trump's tariffs are OK because they were taken under a U.S. national security statute.
In a response to the U.S.' challenge, Mexico's Economy Ministry said Monday that the U.S.' tariffs were imposed "unjustifiably" and the Mexican government would stand by its retaliatory measures.
Mexico said it would issue a response within the next 10 days.
