President Trump visited Ohio on Saturday for a roundtable discussion with small-business owners about the recent GOP tax cuts. But as often the case, he turned the public event into a freewheeling discourse on such key issues as illegal immigration and U.S. trade policy.

He said people entering the U.S. illegally are taking advantage of Democrat-backed "catch-and-release" policies and fail to show up for their immigration court dates.

"We may have to close up our country to get this straight," Trump said at the Cleveland Public Auditorium, while also suggesting that the Democratic incumbent Sen. Sherrod Brown supports open borders.

“We have to have borders,” Trump said. “If you don’t have borders, you don’t have a country.”

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Trump’s 2020 presidential campaign is backing Ohio Rep. Jim Renacci in the GOP bid to unseat Brown.

"He’ll be fantastic,” the president said of Renacci, who attended the event. "We need his vote very badly."

The primary is Tuesday.

Trump also repeated his call to build a wall along the U.S.-Mexico border, and said Mexico should have done more to prevent a large group of Central American migrants from reaching the U.S. border last month -- the so-called "caravan."

Trump while in Ohio also attend a fundraiser for the Republican National Committee, meeting first with high-dollar givers and then addressing a larger group of about 250 donors. The RNC says Trump is raising $3 million.

Trump won battleground Ohio in 2016 by 8 percentage points, and the state has had a Republican governor for roughly 23 of the past 27 years.

The Associated Press contributed to this report.