WASHINGTON — President Barack Obama today dismissed the idea the nation might need a second stimulus to jolt the economy out of recession and urged Americans to be patient with his economic recovery plan.

Faced with rising unemployment numbers and criticism from Republicans who have already labeled the $787 billion stimulus a failure, Obama used his weekly radio and Internet address to remind voters reversing job losses takes time.

He criticized Republicans for opposing the stimulus but offering few alternatives to the worst recession since the Great Depression. And he rejected talk of a second stimulus, an idea that has been discussed by Democrats and even famed investor Warren Buffett.

"We must let it work the way it's supposed to, with the understanding that in any recession, unemployment tends to recover more slowly than other measures of economic activity," Obama, who is visiting Ghana today, said in his recorded message.

The stimulus included $288 billion in tax cuts, dramatic increases in Medicaid spending, about $48 billion in highway and bridge construction and billions more to boost energy efficiency, shore up state budgets and improve schools.

The plan "was not designed to work in four months," Obama said. "It was designed to work over two years."