US government scientists Thursday said anywhere from 20,000 to 40,000 barrels of oil per day could have been leaking out of the ruptured wellhead since the Deepwater Horizon rig sank to the bottom of the ocean on April 22.
The government previously offered a range of 12,000 to 25,000 barrels per day, already making it the worst oil spill in the country's history.
BP's current plans don't "provide the needed collection capacity consistent with the revised flow estimates", said Coast Guard Rear Admiral James Watson, in a letter made public Saturday, to Doug Suttles, BP's chief operating officer for exploration and production.
The new flow estimate means BP may only be collecting about half of the oil through a containment cap that was placed earlier this month over the leaking pipe, which lies about 1.6 km below the ocean surface.
Meanwhile, US President Barack Obama will meet with BP chairman Carl-Henric Svanberg in Washington Wednesday. Obama has faced some criticism in the United States for choosing not to meet with BP officials since the rig explosion sparked the massive spill.
Saturday, Obama told British premier David Cameron that his frustration with BP had "nothing to do with national identity", and that he had no interest in undermining BP's value, the British government said.
British politicians have been uneasy over Obama's anti-BP rhetoric as the company's plunging share price puts a serious dent in the retirement savings of many British households.
During the 30-minute phone conversation, Obama reaffirmed his "deep commitment to the special and historic relationship" between the two countries, the White House said in a statement.
Cameron expressed his "sadness" at the ongoing human and ecological damage in the gulf, but also stressed the importance of BP to the economy of not only the United Kingdom but also the United States and other countries.
Obama has steadily ratcheted up his language amid BP's failure to stop the leak and claimed BP has been slow in paying out claims to local Gulf Coast businesses. British politicians have emphasized that BP is responding to claims and doing all it can to cap the well.
In an opinion piece published Saturday in several Gulf Coast newspapers Obama acknowledged the anger and helplessness caused by the failure to stop the leak.
"I understand the frustration and anger that the people of the Gulf Coast are feeling. I share it. But instead of allowing feelings of anger and frustration to overwhelm our efforts, we must stay focused on the work at hand," he said.
He reaffirmed that BP "is responsible for causing this horrific disaster, and we will hold the company fully accountable and demand that it pay back every dime for the damage caused and lives disrupted".