Earlier, in a statement posted on its website, BP confirmed it is in advanced talks with the US Department of Justice and the Securities & Exchange Commission over the Deepwater disaster.
It said that "proposed resolutions" were "not expected to cover federal civil claims" and others including those under the Clean Water Act and state claims for economic losses
It added: "Until final agreements are reached, there can be no certainty any such resolutions will be entered into".
More top news
The prime minister said there was a "clear and urgent imperative" to give new impetus to stalled negotiations.
Pollution claimed nine million lives in 2015, with air pollution from vehicles and factories accounting for 6.5m deaths, researchers found.
Donald Trump has given himself a "10 out of 10" for the response to the widespread hurricane devastation Puerto Rico suffered.