Washington, Jun 12 (DPA): US President Barack Obama will hold his first meeting next week with top officials from oil giant BP, the White House said Friday, as government scientists said the worst oil spill in US history could be nearly twice as bad as previously thought.

Obama will meet with BP Chairman Carl-Henric Svanberg in Washington Wednesday. It was not clear whether BP Chief Executive Tony Hayward, who has come under harsh criticism from Obama as the face of BP's oil disaster response, would also be present.

Obama has faced some criticism in the United States for choosing not to meet with BP officials since the April 20 explosion of the Deepwater Horizon rig sparked the massive oil spill at the bottom of the Gulf of Mexico.

Discussions with BP's Hayward and others have so far been left to Coast Guard Admiral Thad Allen, who is coordinating the federal government's response to the disaster.

Obama was also set to talk by telephone Saturday morning with British Prime Minister David Cameron, who came to BP's defence Friday amid a developing rift between the two long-time allies.

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.

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 emphasised that BP is responding to claims and doing all it can to cap the well.

US government scientists late Thursday said anywhere from 20,000 to 40,000 barrels of oil per day could have been gushing out of the ruptured wellhead since the rig sunk to the bottom of the ocean 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.

Taking the median new estimate of 30,000 barrels, 1.26 million barrels of oil would have spewed into the Gulf between April 22, when the Deepwater rig sank to the ocean floor, and June 3. The infamous 1989 Exxon Valdez oil spill by contrast leaked about 260,000 barrels off the coast of Alaska.

The new estimate means BP may only be collecting about half of the oil spill through a containment cap that was placed earlier this month over the leaking pipe, which lies about 1.6 km below the ocean surface.

Over the last few days, BP has used the containment cap to siphon about 15,000-16,000 barrels of oil per day to a drill ship on the ocean surface. BP says it is working on ways to increase the amount of oil it can capture over the coming weeks.

Facing growing anger from the Obama administration and US Gulf Coast residents, BP is also weighing whether to suspend dividend payments to shareholders.

Hayward, in a Wall Street Journal interview published Friday, said a second-quarter dividend cut was a possibility, as the British firm deals with the growing costs of a disaster that is threatening livelihoods in four southern US states.

"We are considering all options on the dividend. But no decision has been made," Hayward told the US newspaper. Hayward will also be testifying before the US Congress Thursday.

Obama has slammed BP for plans to pay 10 billion dollars in dividends while stalling on claims from struggling businesses on the US Gulf Coast.