A massive winter storm began dumping fresh snow, ice and sleet across a huge swathe of the US early yesterday, with bitter winds bringing an icy blast to some 100 million people, a third of the country.

High winds and freezing rain threatened to turn roads into deadly ice rinks and knock down trees and power lines and forecasts warned of dangerously cold temperatures.

Predawn television footage showed heavy snow in the plains city of Oklahoma City, Oklahoma and lightning and sleet pounding Dallas, Texas.

Blizzard, winter storm and freezing rain warnings were issued for more than half of the country's 50 states, from North Dakota and Colorado down to New Mexico, then up through Texas, Kansas and Missouri to the Great Lakes region and across Pennsylvania to New England.

For Chicago, the National Weather Service said that the "dangerous, multifaceted and life threatening winter storm" with high winds and heavy snowfall would make travel "impossible" at times.