Company officials have said that Crews on Tuesday started the "static kill" operation intended to plug the damaged BP oil well in the Gulf of Mexico.

It began pumping drilling mud into the well about 3 p. m. CDT, about 2 hours after an injectivity test showed it would be safe to go ahead, the British company said on its Web site.

BP's said, "All operations are being carried out with the guidance and approval of the national incident commander. The aim of these procedures is to assist with the strategy to kill and isolate the well, and will complement the upcoming relief well operation."

It has been reported that the operation is part of the overall effort to permanently plug the well that poured an estimated 206 million gallons of crude into the gulf between April 20, when an explosion on the Deepwater Horizon rig ruptured the well, killing 11 workers and July 15 when it was temporarily capped.

The "static kill" involves pouring mud and possibly cement into the well from above, which would force the oil back into the reservoir, and seal the well. It may take up to 61 hours, officials said, and could be followed by a "bottom kill," after a relief well intercepts the crippled well, estimated to happen between five to seven days after the "static kill" is completed.

The United States has billed "BP and other responsible parties" $222 million for official response and cleanup activities "and we will continue billing them until all the costs are covered," White House press secretary Robert Gibbs said at Tuesday's daily briefing for reporters.

Other fines will include one "that will be based off of the amount of pollution put into the gulf, which I think by any accord will be a substantial fine," Gibbs said.

CNN also reported that meanwhile, Mexican media reported the Mexican government said it is planning to make BP and the United States pay for damages and costs associated with the ruptured well. (With Inputs from Agencies)