OTTAWA -- Calgary Mayor Naheed Nenshi says it's up to the federal government to make the final call on pipeline approvals -- not mayors or provincial premiers.

The ongoing debate over getting western Canada's oil and gas to ocean ports continues to churn as Canada's big city mayors meet for two days of talks in the national capital.

A group of Montreal-area mayors, fronted by former Liberal cabinet minister Denis Coderre, sparked a minor national unity furor last month when they came out against the proposed Energy East pipeline from Alberta to New Brunswick.

B.C. Premier Christy Clark has also placed a set of conditions on a westward pipeline route through her province to the Pacific, raising questions about whether there are effectively regional vetoes over national energy infrastructure projects.

Nenshi says politicians are free to voice their opinions -- just as they are on their preference in dinner vegetables or their thoughts on NHL disciplinary suspensions.

But he says ultimately the federal government is responsible for pipeline approvals, based on the best assessment by the National Energy Board.

"Fundamentally this is a federal government responsibility, so those of us at the municipal order of government or provinces can talk about conditions or whatever we want -- ultimately, it's not our say," Nenshi said Thursday.

The Calgary mayor offered that he doesn't much like Brussels sprouts, but that doesn't mean no one else should eat them.

As for his Montreal mayoral counterpart Coderre, "he's welcome to take a position" on Energy East, said Nenshi.

"I'd love to know what he thinks about (Calgary Flames defenceman Dennis) Wideman's 20-game suspension, too."

Coderre met with Prime Minister Justin Trudeau following his very public critique of the proposed $15.7-billion TransCanada line and toned down his rhetoric. But he bristled Thursday at questions about his right to question the pipeline proposal.

Coderre asked what last December's global Paris climate agreement was all about, including the celebrated participation of "sub-national" governments, if the world is going to continue with business as usual.

"Every time that something happens on our territory, it is normal and imperative that we can take a stand," he said.

Clark, meanwhile, happened to be attending an event in the same Ottawa hotel Thursday, where the B.C. premier defended the five conditions her government has placed on Kinder Morgan's proposed tripling of its Trans Mountain pipeline to Vancouver.

Clark told reporters the conditions -- as yet unmet -- are a means to get approval of the project, rather than a method for shutting it down.

Perhaps the most surprising take Thursday came from Glen Murray, Ontario's minister for environment and climate change, who questioned in an interview whether any new pipelines are needed at all.

"I think the question right now about whether pipelines will be needed is an open question," Murray told The Canadian Press, citing both the market turbulence that's throwing off everyone's projections and the new international consensus on limiting carbon growth.

"I think the question of pipelines will probably be settled as much by the marketplace as it will be by politics in the longer term."