David Cameron said today he understood the US government's "frustration" over BP's efforts to cope with the Deepwater Horizon oil leak and would discuss the situation with President Barack Obama.
The Prime Minister's comments came as London Mayor Boris Johnson accused the US administration of "anti-British rhetoric" as the value of the oil giant's shares plunged.
Speaking in Afghanistan Mr Cameron said: "I understand the US government's frustration because it is a catastrophe for the environment.
"Obviously everyone wants everything to be done that can be done. Of course that is something I will be discussing with the American president."
Asked if he was concerned about the tone of US comments about BP, Foreign Secretary William Hague told the BBC: "No-one has used an anti-British tone in anything I have detected.
"The Prime Minister, of course, will be able to discuss this with President Obama, but the important thing here is actually dealing with the problem that has arisen from that oil spill, dealing with it out at sea and making sure that everything possible is done.
"I think that is more important than any rhetoric that any of us may indulge in about it."
BP's shares plunged as much as 12% today as US officials threatened to seek a ban on dividend payouts following the Gulf of Mexico crisis.
BP rushed out a statement saying it was unaware of any reason for a plunge in its shares in New York overnight and added that its balance sheet was strong enough to deal with the cost of responding to the incident, environmental clean-up and claims from those affected.
But investors were spooked after US Department of Justice officials reportedly said they were planning "to take action" to make sure BP had enough cash to cover claims arising from the spill.
This was seen as a threat to the BP dividend, which has not been cut since 1992 and provides around £1 in every £7 of share payouts from UK blue-chip firms.
Around £50 billion has been wiped off the value of the firm since the Deepwater Horizon oil rig disaster on April 20, which killed 11 workers.
Beleaguered BP added that the cost of the clean-up and containment efforts had now hit 1.43 billion US dollars (£979 million).
But its latest effort to capture oil spewing out of the leak is now collecting about 15,000 barrels a day.
The firm is facing mounting pressure from President Barack Obama over its response to the oil spill, with attacks becoming increasingly aggressive.
President Obama's administration has insisted on referring to BP by its former name "British Petroleum" and the US leader suggested its chief executive, Tony Hayward, should be sacked.
In the past week, he has said he wants to know whose "ass to kick" at BP and slammed the group for spending money on advertising and shareholders while "nickel-and-diming" fishermen and small businesses in the Gulf.
BP employs 22,800 staff in the US, while the region accounts for around a third of its profits and proven oil reserves.
Although the stock later pulled back from the worst of its declines, investors have taken heavy punishment.
Jonathan Jackson, head of equities at stockbroker Killik & Co, said: "Although the newsflow on the spill is more positive, the political environment has clearly deteriorated, with further calls for the group to suspend its dividend until the cost of the spill is met and the Justice Department making noises about taking action against the company."
The company has so far refused to comment on the future of dividends, with the board due to make the decision at the end of July.
But it faces the wrath of the US government over payouts to shareholders while the leak is still pumping out oil into the Gulf at an estimated rate of up to 19,000 barrels a day.
The firm is struggling to control the spill with a containment cap placed over the well last week.
Efforts appear to be improving, with the cap collecting around 15,000 barrels of oil a day on Tuesday and around 7,920 in the first 12 hours of yesterday.
BP is also working on two ways to improve the cap further, while it is drilling two relief wells to provide a longer-term solution - although these will not be finished until August.
The firm has said revenues from the recovered oil as well as liquid skimmed from the sea surface would be put into a new fund to help wildlife habitats along the coastline of Louisiana, Mississippi, Alabama and Florida.
A spokeswoman for the Prime Minister refused to comment on Mr Johnson's criticism of "anti-British rhetoric".
The spokeswoman confirmed that Mr Cameron had only spoken to Mr Obama once since becoming Prime Minister.
She declined to say when the "routine" phone call this weekend had been scheduled, or whether it would become a "regular" call.
"This will be the start of a routine," she added.
The spokeswoman described the spill as an "environmental tragedy", and said the PM shared the "frustrations" of those affected.