There are growing signs of a recovery in the U.S. economy but the high unemployment rate remains a big concern, White House economic adviser Lawrence Summers said on Monday.

Summers said the economic outlook had improved markedly since the credit crisis of 2008-2009 that spurred fears of another Great Depression.

Forecasters are shifting their focus from debating whether there will be a double-dip recession to debating the pace of growth, said Summers, who spoke at the Johns Hopkins School of Advanced International Studies.

But Summers, director of the White House National Economic Council, referred to the millions still out of work in the United States as an economic emergency. The U.S. unemployment rate is currently 9.9 percent.

Listing some of the risks to the U.S. economy, Summers mentioned the European debt crisis, which he said had introduced uncertainty into the global economic outlook, which could have implications for the United States.

(Writing by Caren Bohan in Washington; Editing by Jackie Frank)