US President Barack Obama, in a helicopter scudding low over flattened homes and swamped streets, on Wednesday toured the devastation wrought on New Jersey's coastline by superstorm Sandy.

Obama, taking another day off the campaign trail to manage the response to the disaster despite Tuesday's looming election, offered a show of strength and support to victims and promised to stay with them for the "long haul."

"We will not quit until this is done," Obama said, offering condolences for those whose lives were torn apart when they lost loved ones and promising to cut government red tape to aid the work of rebuilding shattered communities.

The slender Obama made a political odd couple with bulky New Jersey Governor Chris Christie, who has in the past hammered the president for lacking leadership and is a key backer of his Republican rival Mitt Romney.

Christie, often spoken of as a possible 2016 Republican presidential hopeful if Romney loses next week, said it was "very important" that Obama had visited, after pouring praise on the president's handling of the disaster.

"We spent a significant afternoon together," Christie said, adding that the president had "sprung into action" to help provide needed aid to New Jersey, even as they rode in the presidential car.

"I cannot thank the president enough for his personal concern and compassion for our state and the people of our state," Christie said, after bemoaning the "worst storm" he had ever seen in his life.

Obama and Christie clambered aboard the president's Marine One helicopter to fly over New Jersey's Atlantic coast, over houses tipped off their foundations, streets inundated with sand, and still flooded neighborhoods.

In the community of Seaside Heights, Obama saw the twisted iron of an amusement park which took a heavy hit from the storm, and a nearby pier that was ripped apart.

Later, Obama walked, hands in pockets, through Brigantine, holding intense conversations with residents under the eye of his security detail, and accompanied by Federal Emergency Management Agency (FEMA) chief Craig Fugate.

While the White House refused to answer election related questions posed by reporters and the president was off the campaign trail, his trip to meet Christie took place in a highly political context.

His vows that those affected by the disaster would come together and "bounce back" were familiar from his summation of America's response to the financial crisis which threatens his re-election prospects.

While Romney was reduced to appealing for donations to the Red Cross in a muted campaign trip to sunny Florida, Obama strode before the cameras as the commander of a massive relief effort, bristling with presidential authority.

Romney staged three rallies in the Sunshine State, one day after standing down from the campaign trail out of respect for victims of the storm which roared ashore across a vast area of the northeastern US coast on Monday.

Advisor Kevin Madden told reporters that there were so far no plans for the Republican candidate to make his own visit to the disaster zone.

On Thursday, Romney travels to the East Coast state of Virginia, where he had scrapped earlier weekend rallies due to the approaching hurricane.

Obama's response to the devastating storm could help his approval ratings, but both sides believe there are few undecided voters left, so it was unclear whether it would actually shift votes.

While the US media establishment is based on the East Coast and fixated on the storm, key battleground states like Ohio, Iowa, Colorado, Florida, Nevada, and even Virginia largely escaped Sandy's wrath.

With only five days of campaigning left before he asks voters for a second term, Obama will get back to the trail on Thursday, with trips to the battleground states of Wisconsin, Nevada, Colorado and Ohio.

Romney and Obama are closely matched in national polls of their tense race, with the Republican perhaps slightly ahead.

But Obama appears to have the easier path through battleground states to the 270 electoral votes needed to win the presidency.