WASHINGTON – In an early show of optimism, Republicans and Democrats on a powerful committee charged with cutting deficits pledged Thursday to aim higher than their $1.2 trillion target, work to boost job creation and reassure an anxious nation that Congress can solve big problems.

Tax reform as well as cuts to benefit programs such as Social Security and Medicare will be among the options considered, members of the so-called supercommittee emphasized, although no specific proposals were debated at an opening session that ran scarcely an hour.

While they readily acknowledged numerous obstacles to a deal, committee members said it was essential to try at a time the economy is weak, joblessness is high and the country gives every sign of intense frustration with its elected leaders.

The panel, co-chaired by Rep. Jeb Hensarling, R-Texas, and Sen. Patty Murray, D-Wash., lawmakers from opposite ends of the political spectrum, hopes to help broker a deal somewhere in the middle — on an issue where failure is the rule.

Shortly after the session, at least one Republican member, Arizona Sen. Jon Kyl, threatened to quit if the panel considers cuts in defense beyond the $350 billion over a decade that Congress approved last month as part of a package of deep spending reductions and an increase in the debt limit.