U.S. President Barack Obama has declared a state of emergency in the state of Louisiana as tropical storm Isaac nears the country’s Gulf of Mexico, the White House said.

Tropical storm Isaac, which already killed at least 20 people in Haiti and in the Dominican Republic, will possibly reach New Orleans by Tuesday night, nearly seven years after storm Katrina devastated the whole city.

“The President today declared an emergency exists in the State of Louisiana and ordered federal aid to supplement state and local response efforts due to the emergency conditions resulting from Tropical Storm Isaac beginning on August 26, 2012, and continuing,” the White House said in a statement.

The National Hurricane Center (NHC) reported earlier that Isaac could reach the category 2 strength as it would approach New Orleans with top winds of 160 km/h (100 mph).

Category 5 is the maximum on the scale. Hurricane Katrina, the storm which hit New Orleans in 2005, killed some 1,800 people and caused hundreds of billions of dollars in damage.