Despite Tropical Storm Irene’s weakened punch, President Barack Obama urged those in its path to stay vigilant and warned that the storm’s impact would continue to be felt for some time.

“This is not over,” Obama said in a Sunday afternoon statement from the Rose Garden.

With Irene having unleashed furious wind and rain as it carved its way along the East Coast, the president said emergency officials were most concerned about lengthy power outages and flooding as swollen rivers begin to crest. He urged the public to heed the warnings of local officials in the coming days, and said his administration would continue working with cities and states to ensure they were prepared to respond.

“The impacts of this storm will be felt for some time. And the recovery effort will last for weeks or longer,” said Obama, flanked by Homeland Security Secretary Janet Napolitano and Federal Emergency Management Agency Administrator Craig Fugate.

Most areas, including New York City, appeared to have escaped with less damage than first expected.

Death toll hits 18

While Irene was far weaker than expected, at least 18 people died in the storm and early damage estimates were in the billions of dollars. The hurricane first slammed into North Carolina on Saturday with 85-mile-an-hour (140-kilometer-an-hour) winds, before turning north up the coast.

But Obama said the toll could have been much higher had it not been for preparation and coordination by FEMA and other emergency personnel.

“This has been an exemplary effort of how good government at every level should be responsive to people’s needs and work to keep them safe and protect and promote the nation’s prosperity,” the president said.

Strong winds were expected in New York until nightfall Sunday, but the storm – the first hurricane to hit the Big Apple for a generation – was weakening as it continued up towards Boston.

With more flooding possible, government officials warned it will take several days before they can fully assess the storm’s damage.

Obama eyes election amidst storm

The administration has made a concerted effort to present Obama as a president fully engaged in every aspect of the storm, releasing several photos and readouts of Obama’s briefings on Irene as it approached the U.S.

The president cut his Martha’s Vineyard vacation short by about 12 hours to return to Washington ahead of the storm’s arrival.

‘Funds for cities to recover’

Fugate, the FEMA director, said teams first checked on damage in North Carolina, where reports are mostly of flooding, downed trees and damaged highways, and were continuing to move through other affected states as Irene headed north toward Canada.

Fugate said FEMA will work closely with the White House to determine what type of funds may be needed to help cities and states recover.

Obama has already issued emergency declarations for most of the states hit by Irene, including North Carolina, Virginia and New York, in order to make federal resources available to support response efforts.

Evacuees can go back home: NY Mayor

“The good news is the worst is over and we will soon return to restore and return mode,” New York Mayor Michael Bloomberg said.

He announced that 370,000 people ordered to evacuate could now go back home. More than a million evacuees in New Jersey were also starting to return.

The New York Stock Exchange said it was set to reopen as normal Monday morning.

Air travel, power supply hit

Air travel chaos sparked by the closing Saturday of John F. Kennedy International Airport, LaGuardia and Newark also looked likely to drag on. Already more than 10,000 flights were cancelled across the eastern United States. Irene also left swaths of territory without power.

In New Jersey alone, 650,000 people had lost power supplies, the governor said, while in New York City the number reached 62,000 people, Bloomberg said.

The worst outages were in the greater Washington area where nearly two million people lost electricity.

Meanwhile, the National Hurricane Center reported that a new tropical storm, Jose, had formed and was approaching Bermuda.