WASHINGTON — Top negotiators on the budget maintained a conciliatory tone and promised Wednesday to genuinely try to find agreement to spare both the Pentagon and domestic agencies from automatic, indiscriminate spending cuts that are the price for Washington’s repeated failures to strike a fiscal accord.

Members of the official House-Senate negotiating committee may have struck the right notes, but as soon as the session began a familiar rift opened over taxes, with the top GOP negotiator taking a firm stance against using tax revenues to ease the automatic cuts known as sequestration.

“I want to say this from the get-go: If this conference becomes an argument about taxes, we’re not going to get anywhere,” said House Budget Committee Chairman Paul Ryan, R-Wis.

The chief protagonists had already signaled that the idea of a “grand bargain” blending hundreds of billions of dollars in new tax revenues and politically painful savings from fundamental restructuring of benefit programs is highly unlikely. Instead, their efforts are focused on a smaller agreement to smooth the rough edges of the automatic cuts.

The cuts are the consequence of Washington’s failure to strike a follow-up budget pact to a 2011 agreement to cut agency budgets. The threat of the cuts was intended to force the 2011 deficit “supercommittee” to reach an agreement, but the panel failed to do so.

Wednesday’s talks represent a brief cease-fire in a long-running battle over deficits, spending and taxes between Democrats, who control the White House and Senate, and Republicans, who lead the House. President Obama and House Speaker John Boehner, R-Ohio, have yielded the limelight to lieutenants such as Ryan and Senate Budget Committee Chairman Patty Murray, D-Wash.

“We won’t resolve all our differences here. We won’t solve all our problems,” Ryan said. “But we can make a good start.”

Murray said she’s willing to consider longer-term cuts to autopilot-like “mandatory” spending on certain benefit programs in order to ease immediate across-the-board cuts to agency operating budgets.

“I’m ready to make some tough concessions to get a deal,” Murray said. “But compromise runs both ways. While we scour programs to find responsible savings, Republicans are also going to have to work with us to scour the bloated tax code – and close some wasteful tax loopholes and special interest subsidies.”

Lawmakers generally are trying to put together a smaller-scale deal that would ease, for a year or two, the across-the-board sequestration cuts, which began hitting federal agencies in March and threaten more than $100 billion in cuts in the 2014 budget year when measured against spending “caps” agreed to in the 2011 budget pact.

Even achieving a modest agreement will prove challenging. Democrats are pressing to use revenue from ending tax breaks like those awarded the oil and gas industry to ease sequestration and they say they won’t use cuts in domestic programs to help out the Pentagon.

Republicans want to use money from closing tax breaks to reform the loophole-cluttered tax code and lower income tax rates on both individuals and corporations.

Wednesday’s meeting involved speechmaking rather than real negotiating, with lawmakers mostly stating long-held positions rather than exploring avenues for agreement.

“Washington spends more and more and more, and yet our problems are getting worse and worse and worse,” said Rep. Tom Price, R-Ga.

The real action isn’t in the cumbersome 29-member conference committee, but between Ryan and Murray.

The top priority for Democrats is to ease cuts to domestic programs like Head Start preschools, education grants to local schools and infrastructure projects. They want to get the moribund appropriations process – by which Congress passes annual agency budgets – back on track.

Republicans are especially worried about cuts to the Pentagon, which would grow even deeper after the turn of the year.

They are, generally speaking, more willing to let sequestration remain in place.