President Trump cited national security concerns as he expanded his trademark tariffs to cover things like auto parts, nails, staples and electrical wires.

The decision to expand the tariffs came about two years after the first round of tariffs on the imports of raw steel and aluminum, and less than two weeks after Trump signed an initial trade deal with China that pared back the levies on some other goods.

Under the program announced Friday, some imports of products made with aluminum will be subject to an additional 10% duty, while some steel products will be slapped with a 25% tariff.

The announcement said Argentina, Australia, Canada and Mexico are exempt from the higher aluminum tariffs. Those countries, along with Brazil and South Korea, are exempt from the additional steel tariffs.

While imports of aluminum and steel have declined since the Trump administration imposed levies, some products made with those metals “have significantly increased since the imposition of the tariffs and quotas,” according to Trump’s proclamation.

The document states that “aluminum articles and steel articles were being imported into the United States in such quantities and under such circumstances as to threaten to impair the national security of the United States.”

Steel prices rose after the first round of tariffs in March 2018, Bloomberg News reported, but they’re down about 30% since then.