WASHINGTON -- The battle over tariffs and whether they could start a trade war has not stopped making headlines. President Trump stood by his plan to put tariffs on imported steel and aluminum on Monday, despite criticism from the highest levels of his own party.

Mr. Trump may focus on China when he talks about trade deficits, but China provides less than 1 percent of U.S. steel imports. The biggest suppliers are allies like Canada, South Korea, Mexico and Japan -- all of whom fear tariffs and what comes with them.

The president said he will press ahead with tariffs on all imports of steel and aluminum. Details are pending, but Mr. Trump has threatened 25 percent tax on steel and 10 percent tax on aluminum, all in the name of protecting U.S. manufacturers.

"I don't think you'll have a trade war," Mr. Trump said.

But in a rare public split, House Speaker Paul Ryan, R-Wisconsin, said Monday that he fears that countries hit by tariffs could retaliate and hurt U.S. businesses. In a statement, a Ryan spokeswoman said the speaker is "urging the White House to not advance with this plan. The new tax reform law has boosted the economy and we certainly don't want to jeopardize those gains."

White House press secretary Sarah Huckabee Sanders also responded.

"We have a great relationship with Speaker Ryan," she told CBS News. "We're going to continue to have one but that doesn't mean we have to continue to agree on everything. The president has been committed and talked about this for many years."

But will this jeopardize economic growth, as Ryan fears?

"The president feels strongly that we have to protect some of the industries that are the backbone of this country," Sanders responded. "And we have to protect American workers."

The president also linked the tariffs to the renegotiation of the North American Free Trade Agreement (NAFTA), suggesting a new deal could spare Mexico and Canada from the import tax.

"But if I do make a deal which is fair to the workers and to the American people, that would be, I would imagine, one of the points that we'll negotiate," Mr. Trump said. "It will be tariffs on steel for Canada and for Mexico. So we'll see what happens. But right now, 100 percent."

Presidents Johnson, Nixon, Carter, Reagan and George W. Bush all imposed tariffs or took other measures to protect the U.S. steel industry. Bush imposed tariffs in 2002 but withdrew them a year later in the face of international complaints and threats of reciprocal tariffs.