Updated

Vice President Joe Biden is criticizing GOP presidential candidate Mitt Romney for favoring economic policies that Biden says would help some people succeed while leaving the majority of Americans behind.

Biden made the claims in an op-ed published in Friday's editions of The Des Moines Register. Biden singled out Romney in the state where the first votes will be cast in the GOP competition in less than two weeks.

Biden said that Romney's proposals for the economy "would actually double down on the policies that caused the greatest economic calamity since the Great Depression and accelerated a decades-long assault on the middle class."

"Romney also misleadingly suggests that the president and I are creating an `Entitlement Society,' whereby government provides everything for its people without regard to merit, as opposed to what he calls an "Opportunity Society," where everything is merit-based and every man is left to fend for himself," Biden wrote.

After months of criticizing the policies of the Obama administration, Romney has had to focus some of his efforts on former House Speaker Newt Gingrich, who gained significant momentum in recent weeks in his battle for the GOP nomination.

Earlier this week, Romney accused President Obama of deepening the economic crisis and backing policies that would redistribute wealth instead of creating equal opportunity for people to do well.

Romney said his policies would turn the U.S. into an "opportunity society" while Obama's vision for an "entitlement society" would make more people dependent on government welfare.

"The only entitlement we believe in is an America where if you work hard, you can get ahead," Biden wrote in the op-ed.

For his part, Obama has largely refrained from counterattacking his Republican challengers, saying he will wait until voters have settled on a nominee. But Obama's campaign has not, with Biden's column the latest aggressive sign that the Obama team believes Romney is the likely choice to emerge from the field.