Meanwhile, the severe weather threat will linger through Sunday from Florida northward into the upper Ohio River Valley, forecasters warned.

Millions of Americans across the country are on alert for a severe weather outbreak as violent, long-track tornadoes with damaging winds of up to 80 mph and large hail are expected across the Midwest and South with the cross-country storm moveing east.

The president's move follows a deadly storm system over the weekend that has left at least 40 people dead across multiple states.

The death toll from tornadoes and violent storms that ravaged the central and southern United States over the weekend has risen to at least 40 people, with dozens more injured,