British oil giant BP has been given 24 hours to provide details of it next steps to improve its oil containment and clean-up efforts in the Gulf of Mexico, the U.S. commander for the spill said Thursday.

Retired Coast Guard Adm. Thad Allen sent a letter to BP's managing director Bob Dudley Thursday asking the company to hand over "detailed plans and timelines" on stopping the leak in the Gulf of Mexico.

"We are entering a critical stage in the response where key decisions will be made," said Allen, noting that the "decisions also overlap with predictions for an active storm and hurricane season."

Allen demanded BP give details on a third oil containment vessel as well as the timeline for its completion of two relief wells, the best hope of stopping the weeks-old spill in the Gulf of Mexico.

Hurricane Alex already delayed BP's efforts to hook up the Helix Producer containment vessel. BP also considers replacing the current "top cap" with a tighter-fitting "sealing cap."

Officials have planned to set up the Helix first before replacing the "top cap". However, as forecasters predict a window of good weather ahead, hooking up the Helix and replacing the cap simultaneously become possible.

A top BP official said Thursday that the company is hoping to cap the gushing well in the Gulf of Mexico weeks ahead of schedule.

"In a perfect world with no interruptions, it's possible to be ready to stop the well between July 20 and July 27," Dudley was quoted as saying in the Wall Street Journal.