"Which course is better for America? A European model of high taxes and regulations? Or, low taxes and free trade -- the Ronald Reagan model?" Romney asked the Detroit Economic Club audience. "That's the choice the next president will make. Some are already fighting to implement a massive tax increase. Instead, we should make the tax cuts permanent."

Baring the existence of a line-item veto, Romney also said he would reign in federal spending by vetoing any appropriations bill that surpasses a preset spending limit.

"If Congress does not meet the spending targets, then its appropriations bills should be vetoed," Romney said. "I regularly exercised my veto power while governor."

Romney will formally announce his White House bid at the Henry Ford Museum in Dearborn, Michigan Wednesday.

His father, George Romney, was governor of Michigan from 1963 to 1969.

-- CNN Ticker Producer Alexander Mooney