MONTREAL -- Prime Minister Justin Trudeau managed to keep the peace at what began as a tension-filled first ministers meeting Friday but had few concrete achievements to show for the day-long gathering.

The one sour note was sounded by Ontario's Progressive Conservative premier, Doug Ford, who accused Trudeau of moving the goalposts on Canada's climate-change plans, requiring Ontario to cut its greenhouse-gas emissions more than Ford had expected.

But other premiers, including fellow Conservative Brian Pallister from Manitoba, disputed Ford's interpretation of what the prime minister said behind closed doors in Montreal and Trudeau himself dismissed the charge.

Ford at least did not follow through on a threat to walk out of the meeting, which he had criticized for being too narrowly focused on Trudeau's priority -- reducing interprovincial trade barriers -- and not enough on the priorities of provinces and territories.

Trudeau managed to mollify the premiers by letting them talk about whatever they wanted.

"Everything was discussed," said Blaine Higgs, New Brunswick's Conservative premier and the chair of the meeting from the premiers' side. "I was encouraged by the kind of no-holds-barred discussion. That's what we wanted and that's what we got."

Higgs, who had never attended a first ministers meeting before, said many of the others "said this was one of the most productive meetings they've been in for a long time."

Trudeau and all the premiers, including Ford, signed onto a final communique that was long on general statements about working collaboratively to create jobs, grow the economy, protect the environment, reduce red tape and knock down barriers to trade between provinces.

After spending the biggest chunk of time discussing the oil-price crisis that is devastating Alberta's energy industry, everyone agreed in the communique with Alberta Premier Rachel Notley's call for federal support for short-, medium- and long-term help to get her province's oil and gas to ports for shipment overseas.

Alberta has been suffering from a glut of oil that has been trapped inland, away from buyers, because there hasn't been enough transportation capacity to get it out. Customers have only been willing to take it at a steep discount to world prices.

The communique says all agreed the federal government should invest in short-term support for energy businesses hammered by the price differential for Alberta's oil. The federal government should also invest in medium-term efforts to get energy products to market -- which Notley took as supporting her plan to buy tanker cars to move oil by rail -- as well as long-term efforts to build the infrastructure, presumably pipelines, needed to get oil and gas to tidewater.

The communique acknowledged that while all first ministers agree on reducing carbon emissions, they disagree on how to go about it.

"On climate change, I think it's clear that Premier Ford and I differ on the matter," Trudeau said during a closing news conference. "I believe that we need to put a price on pollution ... He believes we should make pollution free again."

Ford's recently unveiled climate-change plan is a "step backwards," Trudeau said, noting that the Ontario premier has scrapped his province's involvement in a cap-and-trade regime with Quebec and California. "Even though the premier may want to play games with numbers, what is clear is we are going to move forward, as we always have, in a very consistent way and if anyone is moving the goalposts, it's Premier Ford."