Presumptive GOP nominee Donald Trump said he believed taxes would go up on the wealthiest Americans under his administration during an interview airing Sunday on ABC, admitting Democrats would force his hand in negotiations over revenues.

This Week host George Stephanopoulos asked Trump if he wanted taxes to go up or down on the rich, despite them going down in his proposed tax plan.

"They will go up a little bit, and they may go up—" Trump started.

"But they're going down in your plan," Stephanopoulos said.

"No, no, in my plan, they're going down, but by the time it's negotiated, they'll go up," Trump said. "When I'm negotiating with the Democrats, I'm putting in a plan. I'm putting in my optimum plan. It's going to be negotiated, George. It's not going to stay there. They're not going to say, ‘There's your plan, let's approve it.' They're going to say, ‘Let's see what we can do.' It'll be a negotiation."

Trump added he didn't "mind" paying more tax. His most important concepts, he said, were lower taxes for businesses and the middle class.

"But in the end, will someone like me or Donald Trump pay more under you tax plan?" Stephanopoulos asked.

"I have a feeling we pay some more," Trump said. "But I'll tell you the middle class is going to pay a lot less. And I wouldn't mind paying more, George. We've got to do something … But business will pay less. The middle class will pay less."

"On the taxes on the wealthy, you say you're willing to pay more?" Stephanopoulos asked.

"I am willing to pay more, and you know what, wealthy are willing to pay more," Trump said. "We've had a very good run."

He denied it was any change from his plan, again insisting it was a negotiation.