Keystone XL pipeline report sees 'no objections'
The US state department has raised no major environmental objections to the Keystone XL oil pipeline from Canada, according to a new report.
Environmentalists say the pipeline will lead to increased carbon emissions, contribute to global warming, and risk spills on its route.
President Barack Obama has yet to decide whether he will permit it.
The 1,179-mile (1,897km) pipeline would carry tar sand oil from Alberta in Canada to Nebraska.
The oil would then be transported on existing pipes to refineries in Texas. The southern section of the project was finished last year.
The Keystone XL project aims to carry some 830,000 barrels of heavy crude a day from the fields in Alberta.
The US still needs to approve 875 miles of the route across American land.
On Friday, a spokesman said the White House was still awaiting further review from other government agencies and the public.
"The president has clearly stated that the project will be in the national interest only if it does not significantly exacerbate the problem of carbon pollution," Matt Lehrich said.
In an environmental impact statement released on Friday, the state department said that approval was "unlikely to significantly impact the rate of extraction in the oil sands or the continued demand for heavy crude oil at refineries in the United States".
The report does not directly recommend approval of the 875-mile section. Rather, it is described as a technical assessment of the project's environmental impact.
The pipeline would be built by TransCanada Corp, which first applied for a permit from the US government in 2008.
TransCanada chief executive Russ Girling said on Friday he was "very pleased" with the report's findings.
The project, estimated at $7bn (£4.26bn), has become a source of significant debate, with environmental groups saying it would contribute to global warming.
The opposition Republicans have long supported the initiative, saying it will boost the US economy, create jobs, and reduce North America's dependence on foreign oil.
"This report from the Obama administration once again confirms that there is no reason for the White House to continue stalling construction of the Keystone XL pipeline," Republican Senate Minority Leader Mitch McConnell said in a statement.
"So, Mr President, no more stalling- no more excuses. Please pick up that pen you've been talking so much about and make this happen. Americans need these jobs."
Environmental groups condemned the report. The National Resources Defense Council said it was "absolutely not in our national interest" to allow its construction.
"Piping the dirtiest oil on the planet through the heart of America would endanger our farms, our communities, our fresh water and our climate," the council's international programme director, Susan Casey-Lefkowitz, said.
Other US agencies, including the Environmental Protection Agency, have 90 days to comment before the state department issues its final recommendation to Mr Obama.