WASHINGTON — Severe spending cuts now the law of the land, President Barack Obama and congressional Republicans refused Saturday to concede any culpability for failing to stave off what both parties acknowledged was a foolhardy way to slash $85 billion in federal spending.

The still-fragile economy braced itself for the gradual but potentially grave impact of the across-the-board cuts, which took effect Friday night at the stroke of Obama’s pen. Hours earlier, he and congressional leaders emerged from a White House meeting no closer to an agreement.

Even as they pledged a renewed effort to retroactively undo the spending cuts, both parties said the blame rests squarely on the other for any damage the cuts might inflict. There were no indications that either side was wavering from entrenched positions that for weeks had prevented progress on a deal to find a way out: Republicans refusing any deal with more tax revenue and Democrats snubbing any deal without it.

“None of this is necessary,” Obama said in his weekly radio and Internet address Saturday. “It’s happening because Republicans in Congress chose this outcome over closing a single wasteful tax loophole that helps reduce the deficit.”

The president said the cuts would cause “a ripple effect across the economy” that would worsen the longer they stay in place, eventually costing more than 750,000 jobs and disrupting the lives of middle-class families.

In the Republican-controlled House, GOP lawmakers washed their hands of the mess, arguing that bills they passed in the last Congress to avert the cuts absolved them of any responsibility. Those bills passed with little to no Democratic support and were never taken up by the Senate.

“We’ve done the work and shown that these choices can be made in a responsible, thoughtful way,” said Rep. Cathy McMorris Rodgers of Washington in the GOP address.

Obama was holding out hope that as Americans start feeling the effects of the sequester — the term used for the automatic spending cuts — public pressure will force lawmakers back to the table. Ever wary that such fiscal fiascos could jeopardize the rest of his second-term agenda, Obama vowed in his weekly address to keep pushing reforms on immigration, preschool, gun violence and transportation.

But attention was already turning to the next major budget hurdles, with less than a month to negotiate a plan to fund the government beyond March 27 and a debt-ceiling clash coming in May.

Hopes that a measure to undo the spending cuts could be wrapped into a March deal to keep the government running dimmed Friday when both Obama and House Speaker John Boehner said they’d prefer to keep the two issues separate.

“I’m hopeful that we won’t have to deal with the threat of a government shutdown while we’re dealing with the sequester at the same time,” Boehner said.