The governments of Canada and the province of Alberta will move forward on a major new oil pipeline after the pair announced a plan to ease concerns of British Columbia and First Nations on the Pacific coast.

Canada’s prime minister, Mark Carney, shuttled between British Columbia and Alberta on Thursday to announce more than C$150bn in new investments in both provinces, part of a broader project of reducing trade with the United States and expanding his country’s presence in overseas markets.

Leaning on the familiar framing of a “more dangerous and divided world”, Carney pledged to strengthen domestic industries, saying in Vancouver that the country needed to “move faster, build bigger and work together”.

Carney promised billions for a port expansion in Vancouver, expanded power infrastructure for a new liquefied natural gas (LNG) terminal and investments in new protections for the endangered southern resident killer whale.

But the marquee project is a new pipeline that follows the route of the existing Trans Mountain pipeline before diverting at the end to a new terminal. The project will transport 1m barrels a day, according to the Alberta government.

Carney said Canada and Alberta would be “equal partners” in the pipeline project, and there would be “a meaningful ownership stake for Indigenous communities”. The two governments would also work to achieve “substantial” methane reductions. Consultations will begin immediately with Indigenous communities, provinces and territories.

Carney said his government would leave in place a longstanding federal ban on tankers loading or unloading oil from British Columbia’s north coast – an environmental safeguard that First Nations have long said is non-negotiable.

Alberta’s premier, Danielle Smith, who had long advocated the northern route – which would have required overturning the tanker ban – said on Wednesday the planned southern route represented “the fastest, most cost-effective path to expanding Canada’s energy exports”. Smith is also under growing pressure from a separatist element in her province to demonstrate that Alberta can sign major energy deals with the federal government.

The shift from a northern pipeline to a southern route reflects both a major shift from Alberta – and a recognition by governments that Indigenous opposition would dramatically slow any new project.

British Columbia’s premier, David Eby, said his government would not fight the pipeline after they “found out the hard way” when they lost a court battle over the original expansion of the Trans Mountain pipeline. He said the new deal had strong safeguards and residents would be “fairly compensated for the environmental risks we would take on any new pipeline project”.

Marilyn Slett, president of the Coastal First Nations and elected chief of the Heiltsuk Nation, called the announcement a “good day” following news that the tanker ban would remain in place.

“British Columbians, Canadians and the First Nations who call this place home want this region to remain protected. There is no technology that can clean up an oil spill at sea, and a single oil spill could destroy our way of life,” she said in a statement. “Protecting our coast is not a barrier to economic prosperity, it is the source of it.”

A number of First Nations had previously pledged to withdraw support for multibillion-dollar LNG projects if the 50-year tanker ban was lifted.

The Climate Action Network said it agreed with Carney’s framing that Canada was in a “treacherous moment of geopolitical instability” but said climate change – not trade partners – was the biggest source of instability. “Continuing to expand fossil fuel production when Canadians are already living with climate chaos is simply dangerous,” the group said.

Expanding the Trans Mountain pipeline represents one of largest and most expensive infrastructure cost overruns in Canadian history. While the pipeline has proven strategically beneficial, it is unclear if taxpayers will ever recoup their investment. “If this was a smart economic venture, if there was any kind of reasonable return on investment to be made, a private company or companies would have put up the cash,” Chris Severson-Baker, executive director of the Pembina Institute, an independent Canadian clean energy thinktank, said in a statement. “Instead, Albertan and Canadian taxpayers will now shoulder the cost of 90% of this project – which will likely run into the tens of billions of dollars.”