HOUSTON (Reuters) – The US government ratcheted up efforts to avert an environmental disaster as a massive oil slick leaking from a ruptured well moved closer to the mouth of the Mississippi River yesterday, menacing the delicate coastline of Louisiana and three other Gulf states.

President Barack Obama pledged to “use every single available resource” and the US military was mobilizing to help contain the spreading spill from the deepwater leak in the Gulf of Mexico.

It is pouring out crude oil at a rate of up to 5,000 barrels (210,000 gallons) a day, according to the National Oceanic and Atmospheric Administration — five times more oil than previously estimated.

The rising threat has deepened fears of severe damage to fisheries, wildlife refuges and tourism in Louisiana, Mississippi, Alabama and Florida.

Louisiana Governor Bobby Jindal, whose state is still recovering from the ravages of Hurricane Katrina in 2005, warned the slick “threatens the state’s natural resources.” He declared a state of emergency and asked the Defense Department for funds to deploy up to 6,000 National Guard troops to help with the expected clean-up.

The spreading oil is about 3 miles (5 km) from a fragile wildlife preserve in marshland at the edge of the Mississippi Delta, which experts said would seriously damage the ecology of the area and could be very difficult to clean up.

Homeland Security Secretary Janet Neopolitano declared it “a spill of national significance,” meaning that federal resources from other regions could be used to fight it.