BP’s top-kill operation finally managed to halt the gush of oil from its ruptured Macondo well at the bottom of the Gulf of Mexico Thursday, although, experts warn that the undersea leak was still far from being permanently solved.

US Coast Guard Admiral, Thad said in an interview with the Los Angeles Times that BP had managed to stop the leak. BP's Engineers had forced enough thick mud into the damaged well head to reduce the upward pressure and prevent oil and gas from gushing out.

Thick drilling mud was pumped at high speed into the ocean floor, which lies 1,500 metres (5,000 feet) under the surface of the sea. According to Officials, the pressure of mud stemmed the leak as BP's engineers worked on filling the well adequately with mud to enable a concrete lid to be put in place. BP and the government reportedly mobilized over 20,000 people to work on stemming the leak and cleaning up the slick. There are 1,300 vessels in the area and over 900,000 metres of boom was put in place to stop the leak. "Over the course of the last 12 to 18 hours, they've been able to force mud down, and not allow any hydrocarbons to come up," said Coastguard Admiral Thad Allen, a US officer on the scene.

The environmental damage caused by the accident, began when BP's Deepwater Horizon rig exploded on 20 April 2010, killing 11 workers.

Meanwhile, Environmental scientists who toured the area by boat recently, described a vast expanse of crude half an inch thick, with no sign of the BP or government cleaning the area.

"We couldn't see into the water at all, one engine quit working .... We are talking about really heavy oil spill out there, and no one is out there cleaning it. No one is out there measuring the scope of the oil Mass." said Mr. Larry Schweiger of the National Wildlife Federation.

After an unsuccessful attempt to halt the flow with a top hat-shaped dome, BP began pumping barge loads of sludge into the well on Wednesday afternoon.

Several hours later, the company was able to reduce the pressure at which it was pumping. Experts considered it a progressive development which meant the well contained a column of mud, rather than a plume of oil.

Scientists warned there was potential for even greater damage with a forecast of an unusually hazardous hurricane season. The national weather service in its yearly forecast for the hurricane season starting June predicted between eight to 14 hurricanes across the Atlantic. Of those, three to seven could be major hurricanes.

"If this outlook holds true, this season could be one of the more active on record," said Jane Lubchenco, the Head of the National Oceanic and Atmospheric Administration, the government agency that oversees the forecast.

Also, President Barack Obama Thursday extended by six months a moratorium on new deep-water drilling permits that began after oil gush started from BP’s well. The president also canceled a proposal to drill for oil off the coast of Virginia and suspended planned drilling by Royal Dutch Shell Plc of exploratory wells in the Arctic off Alaska. Sharply tightened regulations were also planned, focusing on stricter safety standards and controls on oil rigs. Obama also criticized the 'scandalous' relationship between US regulators and the oil companies.

The head of the Minerals Management Service (MMS), Elizabeth Birnbaum who is charged with watching over the oil industry, tendered her resignation. According to a statement from Interior Secretary Ken Salazar, She submitted her resignation on her own terms and her own volition.

Obama said it had been entirely Salazar's decision. The US government also said the amount of oil that has been flowing into the Gulf is more than originally estimated. It is believed that about 12,000 to 25,000 barrels of oil were spewing out of the well daily, higher than the initial forecast of 5,000 barrels per day.