Alberta Premier Alison Redford, who is heading to Washington, D.C., this weekend to lobby for the Keystone XL pipeline, says she remains confident the project will be approved.

"I'm still very optimistic about that," Redford said Thursday after she met with her caucus at Government House.

"I think everything that we're doing right now is about ensuring that we have a more sustainable and stronger record with respect to environmental management."

Redford's trip comes after recent comments from U.S. President Barack Obama and Secretary of State John Kerry about the importance of all nations combatting climate change.

Redford said she will discuss not only the need for Keystone, but also the province's environmental track record.

That record includes a $15 per tonne levy on carbon for large emitters who do not meet legislated limits. Alberta has also invested $167 million in 43 clean energy projects.

"We've always said that that connection between economic development and the environment is fundamental. We've never shied away from that, so that's what we're going to go and continue talking about," said Redford.

"Fundamentally this province — probably more than any other province in Canada — is impacted by these issues, and we want to keep championing those issues."

TransCanada's $7-billion Keystone XL line would take Alberta's heavy oil to refineries on the U.S. Gulf Coast. It still needs the Obama administration's approval because it crosses an international border.

The proposed pipeline has been used by environmentalists who argue short-term reliance on so-called "dirty oil" from carbon-intensive operations will do long-term damage to the environment through global warming.

Last weekend, 20,000 protesters rallied on the National Mall in Washington and marched to the nearby White House to urge Obama to kill the pipeline.

Redford's government sees Keystone as a key component in its plan to expand access to foreign markets to boost the price for its oil.

The price that Alberta gets for its oil has been falling due to lack of pipeline capacity to non-U.S. markets and a glut of oil from the Bakken fields in North Dakota.

That price differential is squeezing Alberta's finances, said Redford. The province is expecting to run up as much as a $4-billion deficit in the current budget year ending March 31.

Redford is to be accompanied in Washington by Environment Minister Diana McQueen.

On Saturday, they are scheduled to attend meetings of the National Governors Association and a reception held by Gary Doer, Canada's ambassador to the U.S. There will also be a dinner meeting planned with Manitoba Premier Greg Selinger, who is co-chairing discussions with Redford about a Canadian energy strategy.

That strategy is exploring ways the provinces, territories and federal government can better work together to develop and market energy resources.

On Sunday, Redford is to appear at a meeting of the Western Governors Association, held by U.S. Interior Secretary Ken Salazar.

The fate of the Keystone line is expected to be decided this spring after the U.S. State Department releases its latest environmental assessment on the revised pipeline route.

The original route was rejected by Obama last year after critics warned it threatened an ecologically sensitive aquifer in Nebraska.

Nebraska Gov. Dave Heineman has since signed off on a new route that bypasses the aquifer.