A wild snowstorm has hit the northeast of the US, causing travel chaos.

Nearly 9000 domestic and international flights have been cancelled.

A state of emergency has been declared in three states - New York, New Jersey and Connecticut.

Every school in New York City has been closed, with streets covered in a blanket of snow.

"Mother Nature is an unpredictable lady sometimes," said New York Governor Andrew Cuomo. "All the forecasts said the storm would hit New York City and Long Island the heaviest. Although it would affect the entire state. We deployed accordingly."

The Pennsylvania area is expecting more than 70cm of snow.

The United Nations Headquarters is closed and Donald Trump's meeting with German Chancellor Angela Merkel has also been rescheduled because of the weather.

1News US correspondent Rebecca Wright told Rachel Smalley while the snowstorm has been downgraded, parts are being hit hard.

"In upstate New York, they're really getting it up there, so lots of the resources from New York City itself are being redeployed where they're getting 30 inches of snow."

LISTEN ABOVE AS REBECCA WRIGHT SPEAKS WITH RACHEL SMALLEY