BP says it temporarily halted drilling on a relief well meant to permanently plug its Gulf of Mexico oil leak while it prepares to test a temporary cap on the well.

Kent Wells, a senior vice president in the company, said at a Wednesday morning news briefing they were delaying drilling by up to 48 hours on the well that is supposed to reach the broken one underground and plug it with mud and cement.

Wells said it was a precaution.

It was the latest delay for BP after it postponed testing of a new cap on top of the well by 24 hours late Tuesday. The cap is a stopgap measure designed to keep the oil in the well or funnel it to ships until the relief well is done.