The United States is launching a formal challenge against Canada with the World Trade Organization.

The challenge stems from Canada’s retaliatory tariffs instated on July 1.

The Liberal government introduced duties on some U.S. imports after the Trump administration slapped Canada with tariffs on steel and aluminum.

The U.S. tariffs were applied on the premise that Canada represents a national security threat.

Foreign Affairs Minister Chrystia Freeland has called that assertion absurd.

On Monday. the U.S. launched a series of separate disputes at the WTO.

Canada, the EU, China, Mexico and Turkey are named over each jurisdiction’s set of countermeasures on American imports.

In a statement released Monday, U.S. Trade Representative Robert Lighthizer says Trump’s tariffs are legitimate and justified.

Lighthizer says trading partners have decided not to work with the Trump administration on the issues.

He says the tariffs that are punishing American workers, farmers and companies.