The U.S. labor market is in for a long, slow recovery, according to The Conference Board.

"The high number of long-term unemployed and individuals working part-time for economic reasons, coupled with the likelihood that many employers remain uncertain that the economy is firmly on a recovery path suggests we could be in for a long, slow labor market recovery," said Christopher Woock of The Conference Board.

Woock co-authored The Conference Board's new report "Labor market transitions: from recession to recovery."

The recent increases in temporary employment signal that businesses aren't convinced the recovery is underway, according to The Conference Board.

In addition, discouraged workers who want a job but have stopped actively looking for one will add pressure on the labor market once they decide to return to the labor force, according to the organization. There are now more than 1 million discouraged workers.

Another factor, The Conference Board said, is that the percentage of unemployed who have been out of work for 27 weeks or more continues to rise, and many of the long-term unemployed may find their skills are no longer required in the new workforce. "This could result in a period where the unemployment rate remains relatively high until these individuals re-tool or find alternative employment matches for their skill sets," according to The Conference Board.