Coastal GasLink must consult further with Indigenous communities along a stretch of its pipeline route at the heart of the Wet'suwet'en conflict, say B.C. officials.

Until then, construction cannot take place along the key, 18-kilometre portion.

The company has been given 30 days by the province's Environmental Assessment Office (EAO) to hold those talks before resubmitting its final report for approval.

Protests in support of the Wet'suwet'en hereditary chiefs who oppose the pipeline on their traditional territory have disrupted cargo and passenger rail traffic across the country.

In a letter, obtained by CBC News, to both sides, the EAO says it received feedback from some Indigenous groups, and this week determined there are particular issues that still need to be addressed in order for the project to go forward.

The project was previously approved by the province, pending certain conditions.

The letter, dated Wednesday, asks the company to provide more details about the pipeline, such as how construction might affect the nearby Unist'ot'en Healing Centre.

Protests in support of the Wet'suwet'en hereditary chiefs who oppose the pipeline have disrupted cargo and passenger rail traffic across the country. (Chantelle Bellrichard/CBC)

"[Coastal GasLink] should make efforts to gather and consider additional information in relation to these activities, including from [Unist'ot'en] Dark House and the Office of the Wet'suwet'en," the letter reads, adding that information should be gathered respectfully.

It goes on to suggest the Dark House — one of the hereditary groups central to the dispute — discuss its concerns or meet directly with Coastal GasLink within the next 30 days.

"[Coastal GasLink] must track all engagement efforts, any feedback received and how it was addressed, incorporated, or otherwise considered."

The EAO will then review the report once it's resubmitted and ultimately decide whether to approve it and allow construction to proceed.

The company says it will respond to the issues raised in the letter and again attempt to engage with the community.

"Coastal GasLink hopes that engagement commences shortly to ensure Dark House concerns are addressed in the 30-day process," the company said in a statement.

It also pointed out the area near the healing centre was behind a blockade until January, and therefore has not seen any construction.

This decision by EAO gives the province grounds to call for their immediate evacuation. - Karla Tait, Unist'ot'en Member

Coastal GasLink said if the EAO approves its updated report after these additional consultations, the "short delay" will not affect the pipeline's overall spring construction schedule.

B.C.'s ministry of environment says the 30-day period allows both sides to engage in open and constructive dialogue.

"This is an example of B.C.'s regulatory system working as it should," George Heyman said in a statement to CBC News.

But members of the Unist'ot'en say they identified gaps in Coastal GasLink's report on how it's meeting those conditions months ago.

"Had the province intervened to confirm the reports' shortcomings, they could have prevented the [RCMP's] injunction enforcement, sparing us the violent removal from our lands and sparing the country the subsequent economic pressures of solidarity actions," said Karla Tait, spokesperson for the healing centre.

She said the continued presence of the company and the RCMP on their territory is unlawful.

"This decision by EAO gives the province grounds to call for their immediate evacuation," Tait said in a statement.