The U.S. Chamber of Commerce, the nation's largest business group and customarily a close ally of President Donald Trump's Republican Party, is launching a campaign on Monday to oppose Trump's trade tariff policies.

With some of America's tightest trading partners imposing retaliatory measures, Trump's approach to tariffs has unsettled financial markets and strained relations between the White House and the Chamber.

The new campaign, detailed first to Reuters, is an aggressive effort by the business lobbying giant.

Using a state-by-state analysis, it argues that Trump is risking a global trade war that will hit the wallets of U.S. consumers.

"The administration is threatening to undermine the economic progress it worked so hard to achieve," said Chamber President Tom Donohue in a statement to Reuters.

"We should seek free and fair trade, but this is just not the way to do it."

Tom Donohue, president of the U.S. Chamber of Commerce, is launching a new campaign to oppose Trump's trade tariff policies. (Pete Marovich/Bloomberg)

The Chamber, which has three million members, historically has worked closely with Republican presidents and praised Trump for signing business tax cuts in December.

But mounting trade tensions have opened a rift with the president.

Nations fighting back

Trump has implemented billions of dollars in tariffs targeted at China, Canada, Mexico and the European Union, saying such moves are needed to offset trade imbalances.

Nations have begun retaliating.

Canada has struck back at U.S. steel and aluminum tariffs by imposing punitive measures on $16.6 billion worth of American goods until Washington relents.

Those tariffs kicked in on Sunday.

China is expected to impose a new 25 per cent tax on soybeans in July. Mexico is adding duties to pork imports.

The EU has targeted $3.2 billion US in American goods exported to the 28-member bloc, including bourbon and Harley Davidson motorcycles.

Pushing back on Trump, the Chamber based a state-by-state analysis on data from the U.S. Department of Commerce and government agencies in China, the EU, Mexico, and Canada.

Trump has previously been persuaded to back off of trade threats with the argument that states that backed him in the 2016 presidential campaign will be hard-hit.

For example, the Chamber said Texas could see $3.9 billion US worth of exports targeted by retaliatory tariffs; Tennessee, $1.4 billion US; and South Carolina, $3 billion US.