WASHINGTON - U.S. President Barack Obama heads off for 10-day vacation on the upscale island resort of Martha's Vineyard Thursday amid criticism his choice of vacation spot is inappropriate given the state of the economy.

The White House defends Obama's desire for time to recharge and spend time with his family. Officials also note that the president is never off the job and say he will also be working on a new jobs plan to be unveiled in a major speech shortly after the Sept. 5 Labor Day holiday.

The planned speech will confront public worries about high unemployment and weak economic growth and will include a broad package of tax cuts, construction work and help for the millions of unemployed Americans who have been unemployed for months, a White House official said Wednesday.

With the speech, Obama hopes to frame the autumn jobs debate by pressuring Republicans in Congress to act or face the voters' wrath.

Republicans immediately cast doubt about any such plan, setting up a fresh economic showdown as the presidential campaign intensifies.

The country is in a deep state of disgust about Washington politics, piling urgency on both parties to help the economy quickly -- or somehow position the other side to take the blame.

The plan for a jobs speech was disclosed as the president was winding up a swing through the Midwestern states of Minnesota, Iowa and Illinois during which voters often asked about jobs and the flagging economy.

To pay for his jobs ideas, Obama will challenge the new "super committee" in Congress to go well beyond its goal of finding $1.5 trillion in deficit reduction, with part of the savings used to cover some of his economy-jolting help without sinking the nation deeper in debt.

But there, too, Obama already faces trouble from Republican members who have ruled out tax hikes.

It's all leading to a campaign for public opinion, the outcome shaping the presidential and congressional elections in 2012.

Obama, as the most visible target for voter ire, is seeking re-election with unemployment running above 9 per cent. No incumbent in recent times has won a second term with the jobless rate anywhere near that high.

The final details of Obama's new economic plan have not been decided, and it is expected to be broader than the proposals known so far.

In Illinois on Wednesday, Obama broadly outlined his plans to help the fragile economy and have the costs covered as part of a broad plan to reduce the deficit. He pledged to present a specific way to do both to the super committee of lawmakers assigned to come up with such a deficit-slicing plan before Thanksgiving.

He also urged the public to pressure their members of Congress to deal with him.

"If you're delivering that message, it's a lot stronger than me delivering that message because you're the folks ultimately that put those members of Congress into office. All right?" Obama said at a town hall in northwest Illinois.

Republicans were underwhelmed by news of another speech, jobs package and deficit plan from the president.

On the campaign trail, Republican presidential front-runner Mitt Romney needled Obama.

"Too little, too late," he said from the key primary state of New Hampshire. "But we appreciate the fact that he's going to devote some time to it -- not just going to be on the bus tour, not just going to be vacationing in Martha's Vineyard."

Nearly 14 million people are out of work, and that doesn't count the millions more who have given up trying to find jobs or who have part-time employment when they want full-time.

The president will propose specific help for the long-term unemployed. Roughly 6.2 million people fit that description, meaning they have been out of work for 6 months or more.