NEW ORLEANS (Bloomberg) — BP Plc's relief well and bottom-kill procedure, aimed at permanently plugging its Gulf of Mexico Macondo well, is suspended until the company completes an analysis of complications that might result in a new oil leak.

BP determined that 1,000 barrels of oil remain trapped in the well after cement was pumped in from the top earlier this month. Now US officials fear some of that could be released, or new leaks may form, when the company pumps in more mud and cement into the bottom of the well for the final plug.

The London-based company will probably need until August 17 to come up with a plan for the so-called bottom kill that won't result in an uncontrolled release of crude, National Incident Commander Thad Allen said during a conference call with reporters yesterday.

"The risk right now is the 1,000 barrels, and BP will have directions to mitigate that," he said. "We will take care of that before we do any bottom kill."

Once BP submits its plan, it may receive permission to finish drilling the relief well and begin pumping mud, Allen said. Alternatively, Allen may order BP to replace the blowout preventer, the assembly of valves atop the well, before resuming drilling, he said yesterday.

Allen asked BP to provide a plan for pressure tests and analysis to assess the stability of the well during the removal of the existing blowout preventer and replacement with a new one. In a written order to BP, Allen also requested evidence that oil won't flow if the current stack of valves is removed.

BP's Development Driller III rig is on standby and ready to proceed with drilling the relief well when directed, BP said in a statement on its website yesterday.

BP previously expected to perform the bottom kill as early as yesterday. The source of the world's largest accidental offshore oil spill was temporarily shut by a stack of valves on July 15 after it spilled about 4.9 million barrels of oil into the Gulf.

The dilemma of how to proceed results from Allen's decision to have BP plug the well with cement from the top after injecting a layer of mud to push gas and oil back into the reservoir, some petroleum engineers said. Leaving the mud in place, then pushing it up and out with cement pumped in from the bottom through the relief well would have been a better solution, they said.

"It would have been easier and safer to kill the well with the relief well," Les Ply, a retired petroleum engineer, said in an e-mailed message. "When it is cemented from the bottom, you can be assured the well is dead."

Once Allen issues an order to resume drilling, it will take BP about four days to reach Macondo with the relief well. When Allen will issue the directive to continue drilling depends on the result of the ordered tests and analysis, he said.

The pressure tests conducted in coming days will also help determine the risk of oil escaping from the undersea reservoir during the bottom kill, Allen said.

The reservoir may have held 50 million to 100 million barrels of oil, BP chief executive officer Tony Hayward said in a May 6 interview with the Houston Chronicle.

President Barack Obama and his family arrived on Florida's Gulf coast yesterday for a trip that's part business and part pleasure, as his administration hopes to provide the region with an economic boost in the aftermath of the disaster.

The Obamas and Navy Secretary Ray Mabus, a former governor of Mississippi who the president directed to develop a restoration plan for the Gulf Coast, met with local small business owners to discuss the recovery.

"I'll not be satisfied until the environment has been restored, no matter how long it takes," Obama said during a press conference in Panama City Beach, Florida. "We're going to continue to monitor and remove any oil that reaches the surface."

Beaches all along the Gulf coast are clean and open for business and the seafood is safe, he also said. Gulf seafood was served at the White House at a barbecue to celebrate Obama's birthday earlier this month.

Any delays in BP paying claims are "unacceptable," Obama also said. "I'll keep pushing to get these claims expedited."

The spill, which started after the Deepwater Horizon rig exploded on April 20 about 40 miles offshore Louisiana, may cost the Gulf Coast region 17,000 jobs and about $1.2 billion in lost economic growth by the end of the year, Moody's Analytics said last month.

A separate analysis by Oxford Economics released by the US Travel Association said the impact on tourism may cost the coastal economy $22.7 billion over three years.