Oil has stopped leaking into Gulf, says BP

BP says it has halted the flow of oil into the Gulf of Mexico for the first time in three months. The energy company finished fitting a new cap over its leaking undersea well on Thursday.

Imagens captadas por vídeo mostram o sistema de contenção instalado pela BP no local do vazamento, no Golfo do México. Reuters

BP's senior vice-president Kent Wells announced the news shortly after engineers shut down the last of three valves on the giant cap.

Over the next 48 hours, the company will carry out tests to analyse the condition of the underground wellbore in the hope of stopping the leak for good.

US President Barack Obama welcomed the development as a "positive sign", but stressed that the cap remains "at the testing phase". He is due to make a statement on the oil spill later on Friday.

The latest tests are intended to determine whether the wellbore was damaged when the  Deepwater Horizon rig leased by BP exploded on 20 April.

If there was damage to the wellbore, the cap stopping the oil flow from the top of the well could force out oil from the other weakened areas.

During the test, engineers will take multiple readings from the capping stack on top of the wellhead to monitor the pressure inside.

After 48 hours, the engineers will open up the system again and begin capturing the oil through two surface vessels to allow a new seismic survey to be carried out.

A permanent solution to the leak is not expected before mid-August, when crews will complete the first of two relief wells, allowing the oil reservoir to be plugged.

"We have been fighting a war against this oil for months now and we know our battles don't end even when the well is capped," said Louisiana Governor Bobby Jindal.

"Millions of gallons of oil are still in the Gulf and some estimates show that oil will continue to hit our shores for many more months or maybe even longer."