President Trump's dream of a 15 percent tax rate for corporations is likely out of reach but a rate in the low 20s and competitive with most industrial countries is feasible, House Speaker Paul Ryan said Thursday.

"Our goal is to get in the mid- to low-twenties," Ryan said, "and we think that is an achievable goal."

Ryan, speaking at an event at the Newseum in Washington, noted a corporate tax rate in the low twenties would bring the U.S. tax rate in line with those of other advanced economies. Today, the statutory rate is 35 percent.

Trump wants a 15 percent rate. Although that goal would be tough to achieve in the tax reform plan Republicans are currently negotiating, which is meant not to lower revenues in the long term, Trump's aides have reasserted it as recently as Wednesday.

"The numbers are hard to make that work," Ryan said of the 15 percent rate, adding he would support getting it that low if possible.

During the public interview with the New York Times, the speaker suggested Republicans are prepared to eliminate major tax breaks in order to drive rates low.

One big idea Ryan previously proposed was to tax corporate tax flows, rather than profits, and adjust the tax at the border. That measure, the border-adjusted tax, would have raised about a trillion dollars in a decade that could have been used in tax reform to drive the corporate tax rate low.

After major backlash from retailers and refiners, however, the Trump administration and GOP leadership agreed to rule the border-adjusted tax out.

"I still think it's a smart way to go, long-term, for our country," Ryan said Thursday.