President Donald Trump’s tariffs on aluminum and steel imports are mostly driven by concerns that China is glutting global markets and hurting U.S. manufacturing, a former trade adviser to the White House said.

“Any steel coming into the United States is going to have a 25% tariff,” he told reporters Sunday on Air Force One as he flew from Florida to New Orleans to attend the Super Bowl. When asked about aluminum, he responded, “aluminum, too” will be subject to the trade penalties.

The European Commission is investigating whether to tighten its current system of quotas on steel imports to protect EU producers from new tariffs U.S. President Donald Trump plans to impose on incoming steel and aluminium on March 12.