U.S. President Barack Obama said Tuesday evening the government will fight the oil spill in Gulf of Mexico "with everything we've got for as long it takes," and used the tragedy to make the case for the nation to embrace clean energy.

In his first oval office address to the nation, Obama said he will do whatever's necessary to help the Gulf Coast and its people recover from the oil spill, already the worst environmental disaster the United States has ever faced.

He recounted efforts made by the government to stop the oil leak in the sunken Deepwater Horizon drilling rig, operated by British oil giant BP before a huge explosion ripped it apart on April 20.

Obama said BP was directed to mobilize additional equipment and technology to stop the leak, and will be able to "capture up to 90 percent of the oil leaking out of the well" in the coming days and weeks, until the company finishes drilling a relief well later in the summer that is expected to stop the leak completely.

U.S. scientists on Tuesday significantly increased estimate of how much oil is spilling into the Gulf, saying the most likely flow rate of oil ranges from 35,000 to 60,000 barrels per day, a jump from last week's estimate of 20,000 to 40,000 barrels per day.

Just returned from a two-day tour to the Gulf Coast, Obama said unlike an earthquake or a hurricane, the oil spill is not a single event that does its damage in a matter of minutes or days.

"The millions of gallons of oil that have spilled into the Gulf of Mexico are more like an epidemic, one that we will be fighting for months and even years," said he.

He then proceeded to lay out the plan forward, which includes how to clean up the oil, how to help coastal states affected by the spill, and how to make sure a similar catastrophe never happens again.

MAKING BP PAY

Saying he won't let the Gulf's way of life perish with this disaster, Obama said the government "will make BP pay for the damage their company has caused."

Obama is to meet with BP chairman Carl-Henric Svanberg on Wednesday, and he will ask BP, whose "recklessness" caused the disaster in the first place, to set aside "whatever resources are required" to compensate workers and business owners harmed by the oil spill. The fund is to be administered by an independent third party, "in order to ensure that all legitimate claims are paid out in a fair and timely manner."

Compensation is part of the equation to restore the Gulf. During the speech, Obama made his commitment to the Gulf Coast that "goes beyond responding to the crisis of the moment," and announced he has asked Ray Mabus, the Secretary of the Navy, to develop a long-term Gulf Coast Restoration Plan as soon as possible.

"BP will pay for the impact this spill has had on the region," Obama vowed.

According to a USA Today/Gallup poll conducted before Obama's address, 71 percent of Americans say the Obama administration has not been tough enough in its dealings with BP, and 59 percent of Americans say BP should shoulder all financial losses resulting from the oil spill, even if those payments ultimately drive the company into bankruptcy.

U.S. lawmakers have demanded BP set aside 20 billion U.S. dollars to pay for the clean-up and compensation. BP has not confirmed it will agree to set up such a fund.

CASE FOR CLEAN ENERGY

Obama seized the opportunity to make the case for clean energy, saying the oil spill is a painful and powerful reminder that "time to embrace a clean energy future is now."

He said although people have known for decades the days of cheap and easily accessible oil were numbered, but have failed to end the country's "addiction to fossil fuels."

He blamed the inaction on oil industry lobbyists, and "a lack of political courage and candor," as the United States has reached the point where it can't afford not to change how it produces and uses energy.

Obama touted that the transition to clean energy has the "potential to grow our economy and create millions of good, middle-class jobs."

He praised a comprehensive energy and climate bill passed last year by the House of Representatives, saying it's a bill that "makes clean energy the profitable kind of energy for America's businesses."

However, the Senate version of the bill has yet to be passed, and commentators doubt that it will ever get passed this year, as many lawmakers face battles during the mid-term elections in November.