As part of the declaration, federal aid will be provided to affected individuals in the counties of Caldwell, Fulton, Graves, Hopkins, Marshall, Muhlenberg, Taylor, and Warren, the statement said.

The aid will include grants for temporary housing and home repairs, loans to cover uninsured property losses, and other programmes to help individuals and business owners recover from the effects of the disaster.

Kentucky governor Andy Beshear formally requested the declaration yesterday after the twisters obliterated the small city of Mayfield and destroyed a candle factory.

Biden received the request and approved it yesterday evening, an administration official said.

The governor said the tornadoes were the most destructive in the state’s history and that even the sturdiest structures of steel and brick were flattened.

One twister tore across 365km of terrain, almost all of that in Kentucky, Beshear said.

The Democratic president had previously declared the storms a federal emergency, enabling the Federal Emergency Management Agency (Fema) to assist in the aftermath as thousands face housing, food, water and power shortages.

But under an emergency declaration assistance is limited to US$5 million, according to the Fema website.

A major disaster declaration has no such limit and “provides a wide range of federal assistance programmes for individuals and public infrastructure, including funds for both emergency and permanent work”, Fema’s website says.