The Keystone XL pipeline only has two options, either it's a go or no go. The massive project continues to tether as U.S. President Barack Obama decides whether to choose climate change over economics. Canadian support for the project, meantime, has gone cold.

"Asia will figure out other sources to get supply from if they can't get it from Canada," Brian Ferguson, Cenovus chief executive, was quoted by Toronto Star as telling a meeting before the Canadian Club.

Russ Girling, chief executive of TransCanada Corp., likened the present predicament the Keystone XL pipeline is in to the Mackenzie Valley gas pipeline. It took the latter six years to get regulatory approval. Over time, prices of natural gas dropped. Project proponents eventually killed the project.

"This is exactly the same thing. When markets come up, you have to take advantage of them ... If you miss an opportunity, you may lose it for decades and decades to come," Mr Girling said.

The project currently tethers, pending review by the U.S. State Department. Aside from that, it crosses international borders, the government is conducting an environmental review to see if the Keystone XL pipeline would aggravate the world's current levels of greenhouse gas emissions.

Essentially, the U.S. State Department wants to buy more time to make a final decision. It has said it will give the public more time to comment on it. After all, it will transport 700,000 barrels of oil a day across six U.S. states to the Texas Gulf Coast from Alberta.

"At some point you have to say the time that it has taken is not appropriate," Senator Heidi Heitkamp, one of the project's strong proponents, said at a news conference.

"Anything that would delay it, anything that would lengthen a comment period, anything that would once again say no to this project by delay, as opposed to no to this project by actual decision-making, will not be viewed very favorably by Congress," Ms Heitkamp said.

What started as strong Canadian support for the proposed Keystone XL pipeline, a US$5.4 billion project that would carry oil sands crude from Canada's Alberta to refineries along the Gulf of Mexico coast, has slowly gone cold.

According to a poll released by Nanos Research Group, Canadian support for the project had dropped from 68 per cent in April 2013 to 52 per cent in December of the same year. Opponents' sentiments likewise surged from 28 per cent to 40 per cent.

The drop certainly has implications for the anti-Keystone movement in both countries, Nik Nanos, president of Nanos Research, told Bloomberg.

"The Canadian government has to be concerned about the erosion of approval in Canada, not just in terms of its impact in Canada but also in terms of the U.S."

"One politician - the president of the United States - can say yes to a great project to create jobs on both sides of the border, help with energy independence and energy security," Canada's U.S. Ambassador Gary Doer and Foreign Affairs Minister John Baird said. "Decision time is upon us."