U.S. President Barack Obama on Thursday welcomed the stoppage of oil flow into the Gulf of Mexico, saying it's a "positive sign" but still in testing phase.

British oil giant BP said on Thursday that oil has stopped leaking from the blown-out well in the Gulf of Mexico as a result of the new cap the company placed over the leak.

It's the first time for BP to completely contain the months- long leak triggered by the explosion of BP-leased Deepwater Horizon drilling rig off the Louisiana coast in late April.