US President Barack Obama makes a statement after a briefing on Hurricane Sandy at FEMA Headquarters in Washington, DC, USA, 28 October 2012. [CFP]

U.S. President Barack Obama on Sunday afternoon called on residents and visitors at East Coast to get prepared for "a serious and big storm" and follow the instructions of state and local authorities as Hurricane Sandy is approaching.

Obama visited the headquarters of the Federal Emergency Management Agency in Washington D.C. on Sunday afternoon to get updated on response efforts for Hurricane Sandy.

After the briefing and a telephone conference with governors and mayors of potentially impacted area, Obama told reporters Hurricane Sandy was "a serious and big storm," urging populations in all the impacted states to "take this seriously."

He called on people to "follow the instructions of your state and local officials because they are going to be providing you with the best advice in terms of how to deal with this storm over the coming days."

Obama also noted that Hurricane Sandy could be unique due to its slow moving. "That means that it may take a long time not only to clear, but also to get, for example, the power companies back in to clear trees and to put things back in place so that folks can start moving back home," he said.

The National Hurricane Center extended its warning on Sunday urging residents of the mid-Atlantic coast to be prepared for life- threatening storm surges.

As of 11 a.m. ET, the storm was about 270 miles (434 km) southeast of Cape Hatteras, North Carolina. Sandy is moving at a speed of 14 miles (23 km) per hour, and is expected to move parallel along the Southeast coast Sunday, approaching the mid- Atlantic coast by Monday night.