WASHINGTON (REUTERS) - Republican presidential frontrunner Donald Trump on Sunday blasted the high salaries of chief executives as a joke and a disgrace and said these were often approved by company boards stacked with the CEO's friends.

Mr Trump, a real estate mogul who has said he plans to use his net worth of US$8.7 billion to fund his White House campaign, said in an interview with CBS' Face the Nation Sunday morning talk show that it was hard to tackle the question of corporate pay.

"It's disgraceful, sometimes the boards rule but I would probably say it's less than 10 per cent, and you see these guys making enormous amounts of money. It's a total and complete joke," he said.

Mr Trump also had a dig at retailer Macy's Inc, which decided to stop selling his menswear line after he described migrants from Mexico to the United States as drug-runners and rapists.

"You'll take a company like, I could say Macy's or I could say many other companies, where they put in their friends as the head of the company and they get whatever they want," he said.

Mr Trump also said his tax plan, to be unveiled in coming weeks, would cut taxes for the middle class and corporations,"but for the hedge fund guys they are going to be paying up".