Washington ? President Barack Obama assured the nation his recovery plan was on track Monday, scrambling to calm Americans unnerved by unemployment rates still persistently rising nearly four months after he signed the biggest economic stimulus in history.

Obama admitted his own dissatisfaction with the progress but said his administration would ramp up stimulus spending in the coming months. The White House acknowledged it has spent only $44 billion, or 5 percent, of the $787 billion stimulus, but that total has always been expected to rise sharply this summer.

“Now we’re in a position to really accelerate,” Obama said.

He also repeated an earlier promise to create or save 600,000 jobs by the end of the summer.

Neither the acceleration nor the jobs goal are new. Both represent a White House repackaging of promises and projects to blunt criticism that the effects haven’t been worth the historic price tag. And the job estimate is so murky, it can never be verified.

The economy has shed 1.6 million jobs since the stimulus measure was signed in February, far overshadowing White House announcements estimating the effort has saved 150,000 jobs. Public opinion of Obama’s handling of the economy has declined along with the jobs data.

For the first time, the administration admitted the economic forecasts it used to sell the stimulus were overly optimistic.

By now, according to earlier White House economic models, the nation’s unemployment rate should be on the decline. The forecasts used to drum up support for the plan projected today’s unemployment would be about 8 percent. Instead, it sits at 9.4 percent, the highest in more than 25 years.

Some analysts believe the White House is still not being realistic, that Obama will be lucky if any real job creation from his recovery effort is seen by the end of the year, let alone the employment explosion he predicts.

“I think these estimates are overly optimistic,” said Arpitha Bykere, a senior analyst with RGE Monitor.

Obama spoke Monday about “modest progress” in the economy, citing fewer jobs lost last month than expected. He said he hopes to build on that in the months ahead with stimulus programs.

“We’ve done more than ever, faster than ever, more responsibly than ever, to get the gears of the economy moving again,” he said.

But he acknowledged, “I’m not satisfied. We’ve got more work to do.”

Americans apparently agree. Obama’s disapproval rating on the economy has risen from 30 percent in February to 42 percent, according to a Gallup poll completed May 31. Sensing weakness on a signature issue of Obama’s presidency, congressional Republicans are renewing their criticisms that the stimulus plan has not shown results, only mounting debt.