Three years after the worst oil spill in US history, BP said Monday it has wrapped up "active" cleanup operations in three US states but continues to patrol a stretch of Louisiana.

The British energy giant has spent $14 billion and 70 million personnel hours scouring the Gulf Coast after an explosion on the Deepwater Horizon drilling rig unleashed millions of barrels into the sea.

It took 87 days to cap BP's runaway well that killed 11 workers, blackened beaches in five states and crippled the region's tourism and fishing industries in a tragedy that riveted the nation.

Despite the massive initial response and cleanup operation, BP wasn't able to collect huge amounts of the oil, which kept washing back up on shore when storms churned up the ocean floor.

BP, which had previously wrapped up its efforts in Texas, said Monday it has received permission from the US Coast Guard to also end active cleanup operations in Mississippi, Alabama and Florida.

"The transition is a significant milestone toward fulfilling our commitment to clean the Gulf shoreline and ensuring that the region's residents and visitors can fully enjoy this majestic environment," said Laura Folse, BP's executive vice president for response and environmental restoration.

"Should residual Macondo oil appear on the shoreline, BP remains committed and prepared to address it under the direction of the Coast Guard."

BP continues to actively work on 84 miles (135 kilometers) of shoreline in Louisiana, which was hardest hit by the disaster.

At its peak in 2010, the response and cleanup effort involved more than 48,000 people who assessed 4,400 miles of shoreline.

They found oil along 1,100 miles and determined that 778 miles required some measure of cleaning.