Oil is no longer spewing into the Gulf of Mexico — at least temporarily — as BP Plc said it choked off the flow from its undersea well that ruptured in April and caused the worst offshore oil spill in U.S. history.

BP said it stopped the leak on Thursday with the tight-sealing containment cap installed three days earlier atop its blown-out well, and awaited on Friday the results of tests on whether the well remains intact.

That’s a key issue as the British energy giant moves to plug the leak permanently with a relief well intended to intersect the ruptured well — which extends 2.5 miles under the seabed — and seal it with mud and cement next month.