DETROIT (AP) — Canada invoked a treaty with the United States and asked a judge on Oct. 4 to suspend litigation over Michigan’s effort to shut down a Great Lakes oil pipeline.

Canadian Foreign Minister Marc Garneau made clear that his government is backing Enbridge, the Calgary-based company that operates Line 5.

READ MORE: Kellogg's Being Sued Over Strawberry Pop-Tarts

Canada said it requested negotiations with the U.S. about the pipeline. It cited a provision in a 1977 treaty that says no public authority in either country can take steps to interfere with the flow of hydrocarbons.

“For more than 65 years, Line 5 has been the safest way to transport Canadian hydrocarbons from western Canada to central Canada, helping provide energy that is essential for heating homes and powering Canada’s economy,” Garneau said.

Line 5 moves about 23 million gallons (87 million liters) of oil and natural gas liquids daily between Superior, Wisconsin, and Sarnia, Ontario, traversing parts of northern Michigan and Wisconsin.

A section of the pipeline runs on the bottom of the Straits of Mackinac, which connects Lake Huron and Lake Michigan at the top of Michigan’s Lower Peninsula. Gov. Gretchen Whitmer and Attorney General Dana Nessel, both Democrats, say Line 5 is a grave threat to the Great Lakes and should be closed to prevent spills.

In a federal court in Michigan, an attorney representing Canada said the treaty’s dispute settlement process must trigger a pause in any litigation.

READ MORE: Target To Open Store In Midtown Detroit

Whitmer said she was disappointed by Canada’s decision to invoke the treaty.

“Rather than taking steps to diversify energy supply and ensure resilience, Canada has channeled its efforts into defending an oil company with an abysmal environmental track record,” Whitmer said, noting a Enbridge pipeline rupture into a southwestern Michigan river in 2010.

A mediator had been working with Michigan and Enbridge to try to reach a settlement about Line 5, but the talks ended Sept. 9 without an agreement.

“We greatly appreciate the efforts of ‘Team Canada,’ from the government of Canada to the provinces of Ontario, Quebec, Alberta, and Saskatchewan, for their commitments and efforts to keep Line 5 open,” Enbridge said Monday.

Before Whitmer took office in 2019, Enbridge had reached a deal with Republican Gov. Rick Snyder to protect the pipeline by building a tunnel by 2024.

Garneau said Canada supports that plan.

MORE NEWS: City of Hamtramck To Handout Water Filters On Oct.26

© 2021 Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.