MONESSEN, Pa. — Donald Trump called for a new era of economic “Americanism” Tuesday, promising to restore millions of lost factory jobs by backing away from decades of U.S. policy that encouraged trade with other nations – a speech that marked significant break from years of Republican Party advocacy for unencumbered international commerce and drew immediate condemnation from GOP business leaders.

In his 35-minute speech, Trump blamed former President Bill Clinton and his wife, Democratic presidential rival Hillary Clinton for the loss of millions of manufacturing jobs.

He threatened to exit the more than two-decade-old North American Free Trade Agreement and vowed to withdraw from the Trans-Pacific Partnership, an agreement among 12 Pacific Rim nations that has yet to take effect.

He pointed to China as a source of many of America’s economic woes, promising to label that country a currency manipulator and slap new tariffs on America’s leading source of imports, a decision that could dramatically increase the cost of consumer goods.

“This wave of globalization has wiped out totally, totally our middle class,” Trump said, standing in front of pallets of recycled aluminum cans on a factory floor. “It doesn’t have to be this way. We can turn it around, and we can turn it around fast.”

Delivered in a hard-hit Pennsylvania steel town, the speech underscored the central message of Trump’s campaign: that policies aimed at boosting international trade – and America’s intervention in wars and disputes abroad – have weakened the country.

It’s an argument that found support among Republican primary voters, especially white, working class Americans whose wages have stagnated in recent years. Trump hopes it will yield similar success among the wider electorate that will decide the general election.

“I promise you, if I become president, we’re going to be working again. We’re going to have great jobs again,” he said.

But he drew a quick and scathing response from the U.S. Chamber of Commerce, a traditional Republican ally and leading business lobby.

“Under Trump’s trade plans, we would see higher prices, fewer jobs, a weaker economy,” the Chamber tweeted, directing readers to a blog post that said Trump’s policies would lead to millions of job losses and a recession.