London, England (CNN) -- British Prime Minister David Cameron will discuss BP, whose leaking well has caused the worst oil spill in U.S. history, when he speaks by phone with U.S. President Barack Obama this weekend, Cameron's office at Downing Street said Friday.
It will be a "routine call" and BP will be one of several issues they discuss, Downing Street said, without providing more information.
The phone call follows concern about anti-British rhetoric from Obama and others in America about BP's role in the disaster.
London Mayor Boris Johnson said the remarks are "slightly worrying" and Piers Morgan, a British TV host and former newspaper editor, said Obama seems to be on "an absolute witch hunt" against the BP boss.
"You know, accidents do happen," Morgan told CNN's "Connect the World" on Thursday night. "There are major issues in terms of safety here, in terms of environmental tragedy that's going on where this spillage is occurring, but I think simply to demand the guy's head on a plate when he's trying to fix it is not sensible politics, and it's slightly self-serving.
"And I, if I was Barack Obama, would cool the rhetoric. I wouldn't make it a British thing, because BP is not a British company anymore, they are an international company. And it's looking to me a little like Brit-bashing."
Johnson told BBC Radio 4 on Thursday he wants to see "cool heads and a bit of calm reflection" about the problem, "rather than endlessly buck-passing and name-calling."
He said many British pension funds are exposed to BP and could be at risk if the company's share price plummets.
"I do think that it starts to become a matter of national concern if a great British company is being continually beaten up on the international airwaves," he said, adding that the disaster is the result of an accident that BP is trying to remedy.
"Ultimately (BP) cannot be faulted because, I'm sorry, it was an accident that took place, and BP, I think, is paying a very, very heavy price indeed."
Obama said earlier this week that he was talking with experts about the oil disaster so "I know whose ass to kick."
U.S. Rep. Anthony Weiner, D-N.Y., who sits on the House Energy and Commerce Committee, said BP was probably lying in its comments about the spill.
"Here's a viewer's guide to BP media briefings: Whenever you hear someone with a British accent talking about this on behalf of British Petroleum, they are not telling you the truth," Weiner told MSNBC this week.
"I think we as a government have been giving them too much credence for the things they've been saying," Weiner said. "Just about everything they've said at some point has turned out to be wrong. So every time they say they're doing something, your first instinct should be, it just ain't true."
U.S. State Department spokesman P.J. Crowley denied Thursday that Obama or the United States is "Britain-bashing" and said it would probably be a topic the president discusses with Cameron on the phone.
He said there are certain to be "ripple effects" as America demands that BP live up to its responsibilities to clean up the spill.
"The British people understand the frustration and anger that the American people are seeing in this," Crowley said. "It is not going to affect our relationship between the United States and Britain."
Crowley said the United States understands "the importance that BP has within British society and the British economy ... but this is ultimately about a private company and its responsibility in light of what's happened in the Gulf."