The country's oil regulator said it issued the order after finding dangerous hydrogen sulfide gas in a production well at the Frade field, 370 kilometers (230 miles) off the Rio de Janeiro state coast.

The agency accused Chevron of failing to inform authorities about the presence of the gas, discovered during an inspection last week. The US company countered that it "conducts regular monitoring of the substance" and has "safety systems and processes in place."

The well accounts for "less than 10 percent" of the field's total production of about 79,000 barrels per day, according to Chevron.

The US company said it "respects the decisions" of the regulatory agency and would respond to the government's requests.

"All Frade production and injection wells are safe and secure," it added.

Last month, a leak in a well operated by Chevron near the Frade field unleashed a crude oil slick in the area, prompting authorities to suspend the company's exploration operations off Rio.

Brazilian authorities say the spill is now under control.

Chevron faces a slew of fines from federal and Rio state authorities that together could exceed $145 million.

The leak could jeopardize Chevron's access to huge new offshore oil fields, which Brazil's National Petroleum agency says have reserves that could surpass 100 billion barrels of high-quality recoverable oil.

But Chevron said it was "confident it will successfully respond to the ANP's concerns and be able to resume operation of its production and injection wells in due time."

A bill introduced followed a similar move in the Senate earlier this week to press President Barack Obama to authorize the project, which has been stalled over environmental concerns.

The House measure would call on US authorities to act within 30 days to issue a permit for the pipeline, after which the project would be considered approved by default.

Ed Whitfield, chairman of the Subcommittee on Energy and Power, said at a hearing Friday the lawmakers were acting as "a direct response to the administration failure to issue a permit for the pipeline."

"The president had a golden opportunity to take bold action and create jobs for America and he declined to do so," Whitfield said.

The Obama administration earlier this month said it would study an alternate route for the oil pipeline, and pushed back its final decision on the project until 2013 -- after next year's presidential elections.

Pipeline operator TransCanada Corp has agreed to reroute the Keystone XL pipeline project after Nebraska lawmakers approved legislation in a special session that would steer clear of the US state's sensitive wetlands.

Environmental activists fear an accident along the 1,700-mile (2,700-kilometer) pipeline would be disastrous for aquifers in central US Great Plains states.

Others oppose the multibillion-dollar project because exploiting the tar sands requires energy that generates a large volume of greenhouse gases that scientists blame for global warming.

Republican Representative Fred Upton backed the move to speed the pipeline, saying, "The president has been using the slogan 'We can't wait' as he travels around the country. But 'wait' is exactly what he told the workers who want to build and support this pipeline."

Democrats said the effort is misdirected by Republicans who have been blocking efforts by the White House to create jobs.

"We all want more jobs, and that's why I support and I think probably all of our witnesses support the president's jobs program, which is being blocked by the Republicans," said California Democrat Henry Waxman.

"Instead, they want to get jobs from areas that benefit some of their best friends, the oil companies particularly. My greatest concern is that Keystone XL would make us more reliant on the dirtiest source of fuel currently available."

In its long-awaited environmental impact statement on the project, the State Department said in August that the pipeline would be safer than most current oil transportation systems. But it later decided more study was needed.

Obama said he supported the decision to "seek additional information" before deciding whether to give the go-ahead to the $7 billion project, which is part of the broader $13 billion Keystone pipeline system.