President Donald Trump delivers remarks to reporters as he meets with members of the House Ways and Means Committee about proposed changes to the U.S. tax code at the White House in Washington, U.S. September 26, 2017.

U.S. President Donald Trump will call on Wednesday for slashing tax rates on businesses and the wealthy as part of a new tax plan that is likely to offer few details about how to pay for the cuts without expanding the federal deficit.

Hammered out over months of talks among Trump aides and top Republicans in Congress, the plan to be unveiled at an event in Indianapolis was expected to propose a 20 percent corporate income tax rate, a new 25 percent tax rate for pass-through businesses such as partnerships, and a reduced 35 percent top income tax rate for individual Americans.

While it would lower the top individual rate from 39.6 percent, the plan was also expected to double the standard deduction, a set amount of income exempt from taxation, for all taxpayers.

"You have to look at the plan in its entirety. It doubles the standard deduction, so in the end, even the lowest rates get a tax cut," said Jim Renacci, a Republican on the tax-writing House of Representatives Ways and Means Committee.

Republicans will say that the tax cuts, widely leaked to the media by a variety of sources in recent days, would be offset by new revenues raised from eliminating tax loopholes, although few if any of those are expected to be named in the plan.

Republicans are also expected to predict that the Trump tax cuts, if approved by Congress, would drive more robust U.S. economic growth, predictions that critics are sure to question.

At a time of slow but steady U.S. economic expansion, the Trump tax-cut package has some support in Congress, even among Republican fiscal hawks who only a short time ago routinely opposed deficit-financed fiscal proposals.

Trump and his Republican allies made completing tax reform in 2017 a top promise of the 2016 election campaign and are under mounting pressure to finish the job since the collapse of the latest Republican effort to overturn the Obamacare healthcare law.

Trump was expected to push lawmakers hard to quickly approve his tax package, despite critics who will say it falls short of the "tax reform" he promised on the campaign trail.

The plan will be the latest in a series of Republican documents outlining tax policy goals, but failing to tackle the tough questions that have defied past administrations' efforts to fix the tax code. It has not been reformed since 1986.