Hurricane Nate has made a second landfall along the US Gulf Coast early on Sunday, after leaving a trail of death and destruction in Central America.

Around 1:30am 05:30 GMT, the US National Hurricane Center said the storm struck about eight kilometres west of Biloxi, Mississippi, where storm surges caused sea water to rise dramatically.

Nate was packing winds of up to 136km/h and was moving northwards at 32km/h.

The hurricane is expected to weaken significantly as it rages over land and is likely to become a tropical storm on Sunday morning, the centre said, adding that it will turn towards the north-northwest and then northeast with an increase in forward speed during the next couple of days.

Mitch Landrieu, mayor of New Orleans, declared a state of emergency, saying on Saturday that his city was preparing for the hurricane as it got stronger.

"I want to reiterate this to the people of New Orleans, we have been through this many, many times - there is no need to panic. We're encouraging the public to do all they can to prepare as we do in every weather event; you have to have a plan," Landrieu said.

Mississippi officials also declared a state of emergency and Louisiana ordered some people to evacuate coastal areas in advance of landfall.

Central America flooding

In Nicaragua, Nate's arrival followed two weeks of near-constant rain that had left the ground saturated and rivers swollen. Authorities placed the whole country on alert and warned of flooding and landslides.

Nicaragua's vice president and spokeswoman, Rosario Murillo, said that at least 11 people had died in that country due to the storm. Earlier Thursday, she had said 15 people had died before later revising to say some of those were still counted as missing.

READ MORE: Nate strengthens to hurricane as it nears US Gulf Coast

She did not give details on all the deaths, but said two women and a man who worked for the Ministry of Health were swept away by a flooded canal in the central municipality of Juigalpa.

Costa Rica's Judicial Investigation Organism blamed seven deaths in that country on the storm and said 15 people were missing. Flooding drove 5,000 residents into emergency shelters.

In Honduras, there were three dead and three missing, according to Oscar Triminio, spokesperson for the country's firefighters.

Damage caused by the storm prompted Costa Rican officials to postpone a World Cup qualifying football match between that country and Honduras, which had been scheduled for Friday night.