WASHINGTON (AP) — Republican presidential candidate Donald Trump is promising to offer a plan within a month to overhaul the tax system, calling himself "king of the tax code."

He's been hinting at such a plan recently, saying that wealthy Americans should pay more.

In a phone-in interview Friday on MSNBC's "Morning Joe" show, Trump says, "I know the hedge fund guys. ... These guys don't really build anything. They shuffle papers back and forth."

Trump says he'll unveil a plan to simplify the tax code and eliminate some deductions, asserting "nobody knows the tax code better than I do."

Trump says hedge fund managers are big supporters of Democrat Hillary Rodham Clinton and GOP rival Jeb Bush and adds, "I will have a plan."

He says hedge fund managers won't be happy.