President Barack Obama will urge his divided nation to unite around common values on Monday, launching his second term with a plea for ideological foes to unpick America's ugly political deadlock.

Obama, sworn in for four more years in a private ceremony on Sunday, will repeat the oath of office before a crowd of thousands wrapped up against the chill at the white-domed Capitol building, which is draped in huge U.S. flags.

After Obama spent an exhausting first term battling the worst economic storm in decades and waging partisan warfare with Republicans, his second inauguration lacks the historic and hopeful promise of the first in 2009. Yet Obama, 51, has a legacy to defend, including a historic health care law and a retrenchment from draining wars abroad, and he is vowing to make good on the promise of a fairer economy, which anchored his re-election win.

He signaled, at a reception for supporters, that he would dwell on the "common good" and the "goodness, the resilience, neighborliness, the patriotism," of Americans when he gives his address.

"What we are celebrating is not the election or the swearing in of the president, what we are doing is celebrating each other and celebrating this incredible nation that we call home," Obama said. "And after we celebrate, let's make sure to work as hard as we can to pass on an America that is worthy not only of our past, but also of our future. "AFP