The six Republican lawmakers on the panel said they would not rule out tax increases as a precondition. But most made clear on Tuesday that they would focus on what several called the nation’s “spending problem.”

Representative Dave Camp of Michigan took pre-emptive aim at a value-added tax, saying, “Washington has borrowed enough from the American people.”

But Senator Richard J. Durbin of Illinois, the second-ranking Senate Democratic leader, denounced suggestions of an administration VAT plan as the “musings of right-wing cable shows.”

He also admonished “bleeding heart liberals” to be open to program reductions to restore fiscal balance. An hour after the commission’s meeting, however, several liberal activists held a conference call with reporters to press for additional spending to create jobs, lower military spending, higher taxes for the wealthy and no cuts in Medicare or Social Security.

Their views were perhaps best reflected on the commission by Representative Jan Schakowsky, Democrat of Illinois. She called for more spending on infrastructure projects and education, saying that “balancing the budget or reducing the debt are, in my mind, not goals in and of themselves.”

Mr. Obama met privately with the commission members at the White House before their meeting at an executive office building across the street. In the Rose Garden afterward, he told reporters that he had insisted that everything be on the negotiating table. That admonition, he has acknowledged, also obliges him to be willing to set aside a campaign promise that all but the wealthiest 5 percent of Americans would not see their federal taxes rise in his term.

The president said that he had inherited a deficit of $1.3 trillion in 2009, with debt projected to rise by $8 trillion over the decade, and that he had taken steps to restrain its growth despite a recession. But he conceded it was not enough to avert fiscal calamity.