CALGARY, Alberta (AP) — TC Energy Corp. gave the go ahead for construction of its $8 billion Keystone XL Pipeline project on Tuesday, with assistance from the Alberta government.

The company formerly known as TransCanada said Alberta has agreed to invest approximately $1.1 billion as equity in the project, which substantially covers planned construction costs through the end of 2020.

The pipeline would transport up to 830,000 barrels (35 million gallons) of crude oil daily from western Canada to terminals on the U.S. Gulf Coast

First proposed in 2008, the pipeline has become emblematic of the tensions between economic development and curbing the fossil fuel emissions that are causing climate change. The Obama administration rejected it, but President Donald Trump revived it and has been a strong supporter.

The remaining 6.9 billion is expected to be funded through a combination of a $4.2-billion project level credit facility to be fully guaranteed by the Alberta government and a $2.7-billion investment by TC Energy.

The company said with pre-construction activities underway, the pipeline is expected to enter service in 2023.

Once the project is complete and in service, TC Energy expects to acquire the Alberta government's equity investment under agreed terms and conditions and refinance the $4.2-billion credit facility in the debt capital markets.

"We thank U.S. President Donald Trump and Alberta Premier Jason Kenney as well as many government officials across North America for their advocacy without which, individually and collectively, this project could not have advanced," TC Energy chief executive Russ Girling said in a statement.

Environmentalists and Native American tribes along the pipeline route say burning the tar sands oil will make climate change worse, and that the pipeline could break and spill oil into waterways like Montana's Missouri River. They have filed numerous lawsuits.