More analysis will be done before integrity testing of the new Deepwater Horizon oil well cap starts, U. S. National Incident Commander Thad Allen said on Tuesday.

He had met with U. S. Energy Secretary Steven Chu, U. S. Geological Survey Director Marcia McNutt and other scientists and geologists, officials from BP and other industry representatives to review how the testing of the well cap a mile below the surface of the Gulf of Mexico will be done, Allen said in statement.

Allen said on Tuesday, "As a result of these discussions, we decided that the process may benefit from additional analysis that will be performed tonight and tomorrow."

Two collection systems, the Helix Producer and the Q4000, are on line and skimmers were being sent to the site in anticipation of any increased oil flow during the transition, he further said.

According to Allen, two relief wells being drilled nearby had reached depths of 17,840 feet and 15,963 feet below the surface.

BP said in a release that the testing, once it starts, could take up to 48 hours and involves closing the cap, "effectively shutting in the well."

The New York Times reported on Tuesday that Doug Suttles, BP's chief operating officer for exploration and production, said if the tests show the pressure rising and holding, with no significant damage to the casing pipe, BP, working with government scientists, could decide to leave the valves closed, effectively shutting off the well.

Suttles said during a briefing on Monday, "The best-case scenario is that pressures rise to the point we anticipate they would. We'd likely be able to keep the well shut in." (With Inputs from Agencies)