Johnson warns of "anti-British" rhetoric over BP
He said the company was paying "a very,very heavy price" for what had been an accident, and pointed out that UK pension funds had a "huge exposure" to BP.
The oil giant has seen its share price slump and faced a series of broadsides from President Barack Obama, as it has struggled to contain the leak.
Advertisement
Hide AdAdvertisement
Hide AdMr Johnson told BBC Radio 4's Today programme: "I do think there's something slightly worrying about the anti-British rhetoric that seems to be permeating from America.
"I would like to see a bit of cool heads rather than endlessly buck-passing and name-calling.
"When you consider the huge exposure of British pension funds to BP it starts to become a matter of national concern if a great British company is being continually beaten up on the airwaves.
"It was an accident that took place and BP is paying a very, very heavy price indeed."