BP has managed to stop the flow of oil that has been leaking into the Gulf of Mexico for the last five weeks, according to the US coastguard.
It comes after a so-called “top-kill” operation to use heavy mud to block the holes in a broken oil well on the sea bed.
BP itself is yet to comment on the success of the plan, saying only that “operations continue.”
The next step would be to use concrete to seal the leak permanently.
Thousands of barrels of oil a day have been spewing into the Gulf, threatening wildlife as well as the livelihoods of local fishermen and economies reliant on tourism.
While an end to the leak would be welcome news, it would by no means be the end of the problem, as President Obama indicated earlier.
“We will not rest until this well is shut, the environment is repaired and the clean-up is complete,” he said.
Earlier on Thursday the White House announced plans to extend a moratorium on deep-sea oil drilling for six months.
Obama has been facing growing public criticism for his handling of the situation; a poll suggests that only a third of Americans approve of his response.
It may be some time before the impact of the spill is fully known; for BP the cost is financial, for Obama it is political. Residents along the southern US coast are concerned by the environmental damage and the knock-on economic effects on their communities.