The cost of helping the US Gulf Coast rebound from the ruinous Gulf of Mexico oil spill could run into the trillions of dollars, a US lawmaker said Thursday after a briefing from top government officials.

"It will take billions of dollars -- even trillions," Democratic Representative Sheila Jackson Lee told reporters, citing "a presentation by the president's team on the BP oil spill" early in the day.

"We will have an ongoing and unending commitment to fixing this disaster," the Texas lawmaker said at a press conference with other representatives calling for blocking an Afghan war spending bill.

An estimated 35,000 to 60,000 barrels of oil a day has been gushing out of a ruptured well since the Deepwater Horizon drilling rig sank on April 22 some 50 miles (80 kilometers) off the coast of Louisiana.

Some 423 miles (681 kilometers) of US shorelines have now been oiled as crude gushes into the sea at an alarming rate, 10 weeks into the worst environmental disaster in US history.