Barack Obama on Saturday thanked first responders and members of the National Guard for their work during superstorm Sandy, an event the US president said caused "terrible devastation" in the eastern United States.

"I toured New Jersey on Wednesday with Governor (Chris) Christie, and witnessed some of the terrible devastation firsthand. It's heartbreaking," the president said in his weekly radio and Internet address.

Entire communities had been "wiped away" and some of the first responders, who repeatedly put themselves in harm's way, had suffered losses of their own, Obama said.

Sandy, which crashed ashore in the eastern United States late Monday, has left at least 95 dead in 15 states and in Canada. The toll in New York City alone rose to 41 and at least 14 died in neighboring New Jersey, where searches of isolated areas are ongoing.

The storm surge flooded vast areas, including parts of the New York subway system, as high winds cut off power to millions of user across the area.

Rushed in to provide assistance, National Guard troops handed out 290,000 meals and 500,000 bottles of water in the first day of an emergency aid operation in New York city, Mayor Michael Bloomberg said.

Nurses and doctors at New York University Medical Center evacuated fragile newborns, firefighters in New York's Queens borough battled a large fire on flooded streets, and Coast Guard crews had saved the crew of a sinking ship off the coast of North Carolina, Obama said.

The president also reassured millions of affected Americans that the country will be there to help them.

"We're Americans," he said. "When times are tough, we're tougher. We put others first. We go that extra mile. We open our hearts and our homes to one another, as one American family. We recover, we rebuild, we come back stronger -- and together we will do that once more."