by Lisa Lambert

WASHINGTON, May 27 (Reuters) - The U.S. economic stimulus plan has created or saved 150,000 jobs since it was enacted 100 days ago, top White House economic officials said on Wednesday, relying on projections instead of an actual tally of workers.

President Barack Obama pressed the U.S. Congress to pass the American Recovery and Reinvestment Act this winter with the promise it would generate or retain at least 3 million jobs.

With the country's unemployment rate standing at 8.9 percent, its highest in more than a quarter of a century, Americans are eager for that promise to come true. But quantifying its realization is proving difficult.

"In every state across this country, people are at work who would not have been so but for the measures in this act," Jared Bernstein, chief economic advisor to Vice President Joe Biden, told a conference call with reporters. "That's a tremendous dose of medicine into an economy that's finally showing some signs of breaking its fever."

The White House, Bernstein said, is projecting what the level of employment would have been if the stimulus had not passed in February. It is then comparing that baseline to actual employment numbers. Using that method, Bernstein also expects another 600,000 jobs to be created or saved in the next 100 days.

Speaking on the same conference call, Rob Nabors, deputy director of the Office of Management and Budget, said that more $112 billion in stimulus money had already been committed over the last 100 days, which means that the money has been promised but not necessarily distributed.

Biden recently said the act is on track to generate or save 3.5 million jobs by September 2010.

U.S. states, though, have asked for further guidance from the White House on definitions of "jobs retained and jobs created" and have said the stimulus plan did not allot any money for them to administer their parts of the plan, which includes collecting the workforce data. The U.S. Congress is currently weighing legislation to provide additional money to states.