Mnuchin responded, "I think the American public will be comfortable with the information they have."
"There's going to be full transparency as we go through the legislative process, what those rules are, so that rich people can't take advantage of it," the treasury secretary said.
Trump touted his tax plan in Indiana on Wednesday, promising the wealthy would not benefit.
“Our framework includes our explicit commitment that tax reform will protect low-income and middle-income households, not the wealthy and well-connected. They can call me all they want, it's not going to help. I'm doing the right thing. And it's not good for me, believe me,” he said.
When Stephanopoulos asked Mnuchin on Sunday how he can “guarantee that the president won't get a tax cut under his plan,” the treasury chief didn't say.
“I've said all along, the objective of the president is that rich people don't get tax cuts,” Mnuchin said. “And we're perfectly comfortable, as we go through this process, we'll explain to the American public how that works and we'll give plenty of examples.”
Mnuchin said the Trump administration aims for all middle-class Americans to get a tax cut, but the specifics are still being worked out.
“You can't make guarantees because every single person's taxes are different," Mnuchin said. "So we can't make that guarantee but we can say that's our objective and that's what we're working to [do] and we want to protect the middle class.”