Pipeline operator TransCanada Corp is seeing strong interest from oil shippers in locking up the remaining space on Keystone XL and expects it to be fully subscribed, says its chief executive.

TransCanada has yet to make a final investment decision on its $8-billion Keystone XL (KXL) expansion that would boost export capacity from Alberta to US refineries. That decision may come late this year or in early 2019, Chief Executive Russ Girling said last week.

In the meantime, the company is talking with shippers to commit crude volumes on KXL and the existing Keystone system, after announcing in January that it had secured 500,000 barrels per day of crude in 20-year commitments for KXL, about two-thirds of its capacity.

“We expect those discussions will lead to additional take-or-pay commitments and we would anticipate that the pipeline’s capacity will be fully subscribed in the coming months,” Girling said on a quarterly conference call reported by Reuters.

The project has pitted environmentalists worried about spills and global warming against industry advocates who say it will shore up discounted Canadian oil prices and attract investment to Alberta’s oil sands. KXL would run from an oil hub at Hardisty, Alberta, to Steele City, Nebraska, where it would join the existing Keystone pipeline system.

KXL cleared a hurdle last week as the Trump administration said an alternative route through Nebraska would not do major harm to water and wildlife.