A weary Barack Obama, eyelids heavy, predicted Friday that the restorative power of sleep and the sunshine of his native Hawaii would restore his wilting fortunes after a bleak year.

The US president began 2013 with a soaring inaugural address laying out an ambitious second term agenda, sensing a mandate for liberal transformation despite a joyless re-election campaign.

He ended it with a ponderous press conference, deflecting dire assessments of his prospects and gingerly testing an optimistic message for 2014: "We are poised to do really good things."

Second term presidencies are always tough, as exhaustion, unmet promises and fading political zeal humble exhausted administrations.

But Obama's prospects look especially cloudy.

His agenda is comprehensively jammed in Congress. Key initiatives like gun control foundered and Obama's approval ratings have plunged to record lows.

Meanwhile, his bond of trust with Americans has been compromised.

To keep his Nobel peace prize company on the shelf, Obama earned the "Lie of the Year" title from a major fact-checking organization for claims he made for his health care reform law.

And there remains a slim window for significant reforms to be squeezed past angry Republicans before American politics is consumed by next year's midterm election campaign.

It was not surprising then, that despite conjuring seasonal cheer by declaring it the "most wonderful press conference of the year" Obama's demeanor was that of someone approaching a painful session at the dentist.

"Has this been the worst year of your presidency?" was the first question, drawing a chuckle from a president who came prepared to stave off the ritual hour of public self-examination craved by the media.

"If you're measuring this by polls, my polls have gone up and down a lot through the course of my career," Obama said.

"You know, the end of the year is always a good time to reflect and see what can you do better next year," said Obama, before swapping midwinter Washington for the balmy Hawaiian isle of Oahu.

"That's how I intend to approach it. I am sure that I will have even better ideas after a couple days of sleep and sun."

Ironically, Obama reached for the economy -- which has dogged him throughout his presidency -- with its sluggish recovery from crisis -- as a harbinger of better days ahead.

He seized on new figures showing that the US economy expanded a healthy 4.1 percent in the third quarter, and noted the dipping unemployment rate and the creation of 2 million jobs this year, as well as rising US gas and oil output.

"We head into next year with an economy that's stronger than it was when we started the year. More Americans are finding work and experiencing the pride of a paycheck," he said.

"Our businesses are positioned for new growth and new jobs. And I firmly believe that 2014 can be a breakthrough year for America."

Since presidential fortunes rise and fall on public perceptions of the economy, Obama may be shrewd to have pinned his hopes on continued expansion.

But history also shows that second term presidential approval ratings are easily squandered but rarely rebuilt.

Obama hit 41 percent in a CNN/ORC poll released an hour before he walked into the White House briefing room.

Praising a rare budget deal between Republicans and Democrats, Obama said there was hope that US politics was not irredeemably stuck -- though he declared it too early to celebrate an outburst of bipartisanship.

Turning abroad, Obama argued that nuclear talks with Iran offer the best hope for a peaceful end to a showdown with the Islamic Republic.

And he snapped that lawmakers keen to look tough by bashing Iran with new sanctions were playing games while he was trying to keep America out of another war.

The closest Obama got to introspection was when he lamented the departure of his rumpled and reclusive Washington fixer Pete Rouse.

"I love that guy," Obama said, of the man he first employed to set up his Senate office back in 2005.

The president was enthused however by the imminent arrival of John Podesta, a wily veteran strategist he has been trying to lure to his White House for years.

But things are unlikely to get easier in the New Year.

Another showdown looms with Republicans over raising the government's borrowing limit, and more glitches in debuting Obamacare would be disastrous.

Obama has also promised Americans he will lay out reforms in January to National Security Agency spying operations after the Edward Snowden affair.

And hopes of a late political surge to his presidency seem slim.

"A midterm victory leading to a Democratic House and Senate is very unlikely," said Thomas Mann, a political scholar at the Brookings Institution.

"It would take a dramatic improvement in the economy, a successful implementation of (health care) and the Republican radicals seriously overplaying their hand."