The Canadian province of Alberta announced Thursday it would pull out of Prime Minister Justin Trudeau's flagship climate change initiative in protest against a court ruling against the expansion of the Trans Mountain pipeline.

A court had earlier quashed the government's approval of expanding the Trans Mountain pipeline to the Pacific, siding with indigenous people worried that increased tanker traffic will harm whales along the coast.

Landlocked Alberta in western Canada, which sits on the world's third largest oil reserves, was set to rely on the pipeline to sell oil to Asian markets via the port of Vancouver.

"As important as climate action is to our province's future I have also always said that taking the next step, in signing on to the federal climate plan, can't happen without the Trans Mountain pipeline," Premier Rachel Notley told reporters in a live address Thursday evening.

"With the Trans Mountain halted and the work on it halted, until the federal government gets its act together, Alberta is pulling out of the federal climate plan," she said.

Trudeau's government introduced a federal carbon tax earlier this year to curb greenhouse gas emissions, set to rise steadily from Can$10 ($7.50) per tonne this year to Can$50 per tonne in 2022.

"Let's be clear, without Alberta that plan isn't worth the paper it's written on," Notley said.

Meanwhile, Trudeau said in a tweet he confirmed to Notley that his government "stands by the TMX expansion project" and "will ensure it moves forward in the right way".

In addition to Alberta, the provinces of Saskatchewan and Ontario in mid-July announced an alliance against the carbon tax , which they believe is harmful to the economy.

Ontario, Canada's richest and most populous province, elected a climate-sceptic prime minister in June, who is working to dismantle climate change policies.