Senate Majority Leader Harry Reid said Tuesday he would consider legislation forcing construction of a controversial US-to-Canada oil pipeline, setting up a possible end run around the Obama administration after the project's latest delay.

"I'm open to anything that will move energy efficiency," Reid told reporters when asked about negotiations over bringing the Keystone XL Pipeline to a vote.

The top Democrat's potential acquiescence on the issue is crucial because as majority leader he controls the chamber's schedule.

He said the effort was originally going to be a non-binding resolution.

But after the State Department extended the Keystone review process until likely beyond mid-term congressional elections in November, lawmakers shifted toward a measure that carries the power of law.

"Now they say that they want an up or down (vote) on a piece of legislation," Reid said.

The pipeline, first proposed in 2008, is slated to cross US borders bringing oil from the tar sands of Alberta to refineries in the US state of Nebraska and then farther south to Texas.

Republicans have long argued the project would create tens of thousands of jobs. Democrats have countered it carries too many environmental risks.

Reid signalled talks had made progress in the past 24 hours, when he met with Republican senators as well as Democrat Mary Landrieu who supports the project and has voiced opposition to the White House foot-dragging on Keystone.

The effort would need 60 votes in the 100-seat chamber to overcome blocking tactics by Democrats, many of whom are unlikely to buck President Barack Obama's opposition to Keystone.

Some Democrats in Keystone-affected states, or who like Landrieu face tough re-election fights in November in Republican-leaning states, back the effort.

"I think there's probably 15 or more Democrats" who back the pipeline, bringing the total to more than 60 supporters, Senate Democrat Mark Begich of Alaska told AFP.

Should Obama veto the measure, the Senate would need a two-thirds majority, or 67 votes, to override the president.

"A lot of us have argued, put it up, let's see where it falls and then go from there," Begich said.

The Republican-led House of Representatives has passed pro-Keystone bills by wide margins.

Senate Republican John Thune said he hoped the measure could be introduced as an amendment to a broader Senate energy bill up for debate next week.