"I also want to point out that as a result of the cleanup effort, beaches all along the Gulf Coast are clean and safe and open for business," he said.

Panama City had been a popular tourist destination, but its beaches have been fouled by tar balls from the spill.

Environmentally devastating

Obama also used his address to thank coast guard officers for "the largest response to an environmental disaster in American history".

The US sent 7,000 ships and more than 47,000 people to combat the oil spill, which has been environmentally devastating and politically problematic for the Obama administration.

in depth

Some politicans and Gulf coast residents have criticised the US president for his handling of the disaster.

But Gayle Oberst, the Panama City Beach mayor, welcomed Obama's visit as a likely boost for the region.

"I think it's wonderful because we could not buy that kind of marketing," he told the local News Herald newspaper ahead of Obama's visit.

The oil leak in the Gulf of Mexico was caused by an explosion on the Deepwater Horizon rig on April 20, which caused it to collapse and fracture the well head. Eleven people were killed in the incident.

BP, owner of the destroyed rig, was ordered by Obama to set up $20bn fund to pay claims from individuals and businesses hit by the disaster, which saw an estimated 4.9 million barrels of oil pour into the Gulf.

Hotel owners, tour operators and other businesses have already submitted thousands of damages claims to BP, saying that the spill has kept many tourists away during the lucrative summer season.

The company also faces lawsuits, with potential claims for damages in the billions of dollars. 

Oil dispersed

The US government published a report earlier this month saying that nearly three quarters of the spilled crude had now been mopped up or dispersed.

US scientists said in the inter-agency report that burning, skimming and direct recovery had removed one quarter of the oil.

The US government sent 7,000 ships to help tackle the massive oil spill [Gallo/Getty]

Another 25 per cent had naturally evaporated or dissolved, and 24 per cent had been dispersed, either naturally or chemically, the report said.

"Now, as a result of the massive cleanup operation that has already taken place, a recent report by our top scientists found that the majority of oil has now evaporated or dispersed, or it's been burned, skimmed, or recovered from the wellhead," Obama said on Saturday.

"But I won't be satisfied until the environment has been restored, no matter how long it takes."

The clean-up effort has already reopened more than 45,000 square kilometres of fishing grounds and the president said he had already begun eating seafood from the Gulf.

More than one million barrels of oil remains in the Gulf, four times the estimated 257,000 barrels that spilled into Prince William Sound from the Exxon Valdez tanker in 1989.