Donald Trump signaled in remarks broadcast on Sunday that he would consider raising taxes on wealthy US citizens, and that his tax plan unveiled so far was not set in stone.

Asked on ABC's This Week to clarify his stance on taxation, the presumptive Republican nominee said he did not expect his proposals for cutting taxes across the board to make it intact through the US Congress.

"By the time it gets negotiated, it's going to be a different plan," Trump said. "And in my opinion the taxes for the rich will go up somewhat."