President Trump, frustrated with a Supreme Court ruling this month that blocked a key environmental permit, preventing substantial U.S. construction on the Keystone XL oil pipeline, has approved the existing pipeline in place to ship 29% more Canadian crude into the U.S. Midwest and Gulf Coast.

Trump issued a new presidential permit for the base Keystone line, allowing TC to boost capacity by 170,000 barrels per day (bpd) to 761,000 bpd, TC spokesman Terry Cunha said on Thursday. The first 50,000 bpd increment begins flowing next year.

TC CEO Russ Girling said the additional Canadian crude oil on the line will help meet growing U.S. refinery demand.

When Trump came to office, he revived TC's proposed Keystone XL pipeline, which has been delayed by opposition from landowners, environmental groups and tribes. It would give Canada expanded access to its top oil market after its existing pipelines ran full in recent years.

TC expects Keystone XL to enter service in 2023. Construction is underway in Canada, and TC is working on a revised 2020 U.S. work plan focusing on areas that have all permits and approvals, Girling said.

Steep declines in oil and gas production have hurt pipeline operators.