WASHINGTON (AFP) - US President Barack Obama sought on Monday to shield his ambitious second-term agenda from the poisoned political aftermath of a budget fight with Republicans that triggered an US$85 billion (S$105.8 billion) austerity hit.

Mr Obama gathered his cabinet for their first meeting since his second inauguration and vowed to press ahead with action on nurturing economic growth, curbing gun violence and working towards comprehensive immigration reform.

The president also named three new cabinet nominees, signaling an attempt to press ahead on energy innovation and combating climate change, two issues that were at the heart of his State of the Union address last month.

Mr Obama promoted what he said was a "very robust agenda," that would go on even as government departments cope with the disruption from the arbitrary across-the-board budget cuts known as the sequester.

"My agenda obviously is broader than just the sequester," Mr Obama said in the cabinet room of the White House, sitting beside his new Defence Secretary Chuck Hagel and opposite new Treasury chief Jacob Lew.

"One of the things I have instructed not just my White House, but every agency is ... that regardless of some of the challenges they may face because of sequestration - we are not going to stop working on behalf of the American people." The president said Vice-President Joe Biden would update cabinet members on his push for new gun control laws and said he was also looking for action on a bipartisan immigration reform bill.

Aides said Mr Obama had at the weekend reached out to some Republican senators in the hope of crafting a solution to sequestration, triggered by his failed efforts to agree a deficit reduction deal with Republicans.

There are fears the fragile US economy will take a serious hit with the cuts to domestic and defense spending, and are described by Mr Obama as a "meat cleaver" approach.

"It is not right way to go about deficit reduction. It makes sense for us to take a balanced approach that takes a long view," Mr Obama said.

The president wants to cut US debt with a mix of spending cuts and extra revenue accrued by closing tax loopholes enjoyed by the rich and big corporations. Republicans on Capitol Hill are refusing to accept revenue hikes.

After mounting a sharp public relations campaign before the cuts hit on Friday, raising the specter of trouble for emergency services and multiple furloughs for shipyard workers, Mr Obama took a more moderate tone Monday.

He warned that the cuts would "eventually" cause widespread pain. White House aides believe that when the full impact of sequestration comes into view, Republicans may be under more pressure to compromise.

The measures could mean long waits at US border posts, reduced military readiness, cuts to special needs education programs, and the curtailment of some emergency medical services, according to White House officials.

Homeland Security Secretary Janet Napolitano said Monday that travelers at US airports were already facing longer lines and delays, as the cuts hit security screenings and air traffic control.

The cuts were never meant to take effect but rather were a poisoned pill clause attached to the 2011 agreement to raise the debt ceiling, and designed to be so scary that lawmakers would find a less drastic way to cut the deficit.

But such is the dysfunction in Washington and antipathy between Mr Obama and Republicans that no deal was done and the cuts came into force.

Seeking to give an impression of vigor in his second term, Mr Obama named a new budget chief, energy secretary and head of the Environmental Protection Agency.

The president picked top air quality official Gina McCarthy to head the EPA, physicist Ernest Moniz to lead the Energy Department and Sylvia Mathews Burwell to be the new director of the Office of Management and Budget (OMB).

All three nominees must be confirmed by the Senate.

"I can promise you that as soon as the Senate gives them the go-ahead, they are going to hit the ground running and they're going to help make America a stronger and more prosperous country," Mr Obama said at the White House.