New York City's public transport system is to be suspended today ahead of the arrival of Hurricane Sandy.

Governor Andrew Cuomo said the subway, bus and train services would shut down from 7pm (11pm GMT) on Sunday.

As many as 375,000 people have been ordered to evacuate low-lying areas, and schools will be shut.

Sandy's winds are set to intensify as it merges with a wintry storm from the western US. A number of states on the East Coast have declared an emergency.

Up to 60 million people could be affected by the storm, which is set to hit several states key to the November 6 presidential elections.

The two presidential election contenders have modified their campaign engagements. President Barack Obama described the storm as 'big, serious and slow-moving' - and said it would pose additional problems.

'It is important for us to respond big and to respond fast,' he said after a meeting at the Federal Emergency Management Agency (Fema).

Asked whether the storm would affect the vote, Mr Obama said: 'We don't anticipate that at this point but we're obviously going to have to take a look.'

Republican candidate Mitt Romney cancelled an event scheduled for Sunday in Virginia, a key election state, because of the weather, and instead headed to Ohio.

Sandy has already killed 60 people in the Caribbean during the past week.

Dozens of flights to and from the east coast of America have been cancelled due to the threat of Hurricane Sandy.

British Airways has grounded all flights to and from the US Eastern Seaboard, including New York, Baltimore, Washington, Boston and Philadelphia.

A number of BA flights from the US to London have also been halted.

Virgin Atlantic has cancelled flights to and from New York, Washington and Boston.

A statement on BA's website said: 'We understand that customers may be disappointed, however their safety is our highest priority. We are offering the option to rebook or receive a refund to those customers whose flights are cancelled.

'We have also received reports that public transport links to East Coast US airports may be disrupted so advise customers to review their flight and local travel plans before leaving for the airport.'

A spokesman for Virgin Atlantic said last night: 'Passenger and crew safety is our number one priority and we are continuously liaising with local authorities to assess the situation and minimise the disruption caused to passengers.

'We advise all passengers to check our website: www.virginatlantic.com for the latest updates and advice.'

Heathrow Airport is advising passengers who are due to fly to the US today to check the status of their flight with their airline before travelling.

Hurricane Sandy is threatening 50 million people on America's heavily-populated East Coast today and forecasters warned that New York could bear the brunt of the one-of-a-kind superstorm.

Forecasters warned the megastorm could wreak havoc over 800 miles from the East Coast to the Great Lakes. States of emergency were declared from North Carolina to Connecticut.

Have you been affected by Hurricane Sandy or have you had travel plans disrupted as a result of the storm? Email your details to peter.walsh@archant.co.uk