U.S. Republican presidential candidate Donald Trump said Sunday he is open to raising taxes for the rich, backing off his prior proposal to reduce taxes on all Americans and breaking with one of his party's core policies dating back to the 1990s.

"I am willing to pay more, and you know what, the wealthy are willing to pay more," Trump told ABC's "This Week."

After effectively sealing the Republican nomination for the Nov. 8 presidential election last week, Trump has used speeches and interviews to offer more details on his policy positions.