British Columbia is delaying a decision on a controversial stretch of the Coastal GasLink pipeline and asking TC Energy Corp. to take more time to engage with indigenous groups after weeks of debilitating protest blockades along Canada’s rail network.

In an emailed letter to TC Energy, the province’s Environmental Assessment Office said it needs additional information to make a decision on the 18-kilometer (11.2 mile) stretch of the proposed pipeline. It gave Coastal GasLink 30 days to engage with the indigenous groups and update a report.

In separate letters, the agency asked the Dark House and Wet’suwet’en hereditary chiefs to share feedback with the company, particularly about the pipeline’s potential impact on a healing center.

“As expressed in these letters, the EAO is aware that there may be additional information that Dark House and the Office of the Wet’suwet’en may be able to provide to Coastal GasLink for inclusion” in its report “to further minimize or avoid the effects of project construction,” the agency wrote on its website.

The letters were sent Feb. 19-20 as blockades entered a third week, shutting down freight traffic in eastern Canada and halting to most intercity passenger service. Prime Minister Justin Trudeau on Friday acknowledged that his government’s efforts to negotiate a solution have failed and signaled he would be open to police intervention.

“Coastal GasLink will respond to the issues raised in the letter by the EAO and attempt to engage with Dark House on issues raised in their correspondence to the EAO,” it said in an emailed statement. If approval is secured shortly after the end of the 30-day process, “this short delay will not impact our spring construction schedule.”

Environmental and indigenous-rights activists have obstructed rail lines in several provinces, protesting the construction of the planned C$6.6 project ($5 billion) pipeline. It would ship natural gas to an LNG export facility under construction on the British Columbian coast that is backed by Royal Dutch Shell Plc, PetroChina Co. and three other partners.

On Friday, Wet’suwet’en hereditary chiefs indicated they are standing firm in their demands that the RCMP depart from their traditional lands, and that all construction on the Coastal GasLink project stop before “nation to nation” dialog can begin between the indigenous group and the governments of British Columbia and Canada.

The report the company submitted to the EAO “had numerous omissions and several areas that we were concerned weren’t reflected,” Dark House member Karla Tait said in a phone interview.

“We would look to inform that process so that is can be an accurate reflexion of the impacts on our territory,” said Tait, who’s also the volunteer director of clinical programming at the Unist’ot’en Healing Centre.

The Office of the Wet’suwet’en hereditary chief didn’t immediately respond to an email seeking comment.