It was about 495 miles south-southeast of the mouth of the Mississippi River.
The winds could cause significant power outages, and storm surges are projected to be six to nine feet (1.8 to 2.7 meters) high, he added.
The hurricane has continued to strengthen slightly, since becoming a hurricane Friday night, and now has sustained winds of 85 mph, with higher gusts, the National Hurricane Center said Saturday morning.
A storm surge warning has been issued from Morgan City, Louisiana, to the Alabama-Florida border.
Trump has approved a number of disaster declarations for states in recent months preparing for Hurricanes Harvey, Irma and Maria, which primarily affected Texas, Florida and Puerto Rico, respectively.
Bryce Harper, Ryan Zimmerman hit clutch home runs late in Nationals-Cubs
But few can claim the brand of baseball bitterness that has resided here for 84 seasons, spread over three different franchises. But they acknowledged the sixth inning and offensive struggles contributed to them falling behind in the best-of-five series.
The worst tornado and waterspout impacts will occur from now through early Sunday morning.
A tropical storm warning is in effect for.
The minimum central pressure is 984 mb. The hurricane center said the deepest water will occur along the immediate coast near and to the east of the point where Nate makes landfall.
Tropical Storm Nate continues to gather strength at it moves toward the Gulf of Mexico.
After that, it will turn north, then turn north-northeast Sunday. It's moving north-northwest at 21 mph.
Asociación Mexicana de Futbolistas, una realidad
Hoy en día contamos con la unión y con el poder necesario para hacerla y llevar a cabo este sueño para los futbolistas mexicanos. Es ir paso a paso, pero con paso firme".
The so-called cone of uncertainty shows that Nate could hit anywhere in Louisiana, Mississippi, Alabama or the edge of the Florida Panhandle.
Hurricane Nate on Saturday is rapidly moving through the Gulf of Mexico.
The greatest threat from this particular storm is not rain, but strong winds and storm surge, Landrieu said.
Trump issued the declaration Friday, allowing federal assistance to supplement state and local efforts.
VENEZUELA: Nicaragua suma dos muertos y nueve desaparecidos por tormenta tropical Nate
Una alerta amarilla está en vigor en Nicaragua , lo que manda a las autoridades a estar listas para actuar ante un posible desastre.