Powerful nor'easter brings flooding, power outages, and travel chaos across northeastern US

Tens of millions of people across the north-eastern US are in the path of a powerful storm that has already brought coastal flooding, power cuts, travel chaos and cancelled stadium events.

Peaking on Saturday, the so-called nor'easter will "bring dangerous coastal flooding and beach conditions, strong winds and heavy rainfall" to areas including New York City and Boston, the US National Weather Service (NWS) said.

States of emergency have been declared in New York and New Jersey, the latter of which is already facing a coastal deluge in some areas. Rain and strong winds are forecast from Virginia to Maine.

Ed Sheeran's much-awaited Boston concert was among events called off due to the weather.

The nor'easter is already causing widespread power cuts. Nearly 150,000 households have so far lost electricity, according to tracker PowerOutage.

The Federal Aviation Administration recommended air passengers check with airlines about their flight status. More than 1,100 flights have been delayed and another 400 grounded, according to FlightAware.

Saturday's full moon is projected to worsen coastal flooding. Streets and homes were inundated with floodwater in the coastal New Jersey communities of Surf City and Manasquan on Saturday.

"I urge all New Jerseyans to take this storm seriously, stay alert and follow local guidance," Governor Mikie Sherrill said.