BBC News with Marion Marshall.

The northeast coast of the United States is beginning a massive

clear-up

after being hit by the biggest storm for years. At least 30 people have been killed. The mayor of New York Michael Bloomberg said bridges and roads were being reopened, but it would take days to restore power and public transport.

In addition to the lives we lost, the damage we suffered across the city is clearly extensive and it will not be repaired overnight. The two biggest challenges facing our city going forward are getting our mass transit system up and running and

restoring

power. So clearly the challenges our city faces in the coming days are enormous.

New Jersey where the storm made

landfall

was also badly hit. Houses were torn from their foundations and towns flooded after levees broke. The storm has now moved northwest and it has mixed with the cold weather system causing

blizzards

. The White House says President Obama has cancelled a third day of campaigning for next week's presidential election, so he can supervise the cleanup operation. He spoke to reporters at the Red Cross in Washington.

My message to the governors and mayors and, through them, to the communities that have been hit so hard is that we are gonna do everything we can to get resources to you and make sure that any unmet need is identified, we are responding to it as quickly as possible. And I told the mayors and governors if they're getting no for an answer somewhere in the federal government, they can call me personally at the White House.