A politically diverse group of Canadian leaders is expressing disappointment that U.S. President Barack Obama has rejected the Keystone XL pipeline.

Among those who criticized the decision are Liberal Prime Minister Justin Trudeau, Conservative interim leader Rona Ambrose, NDP Alberta Premier Rachel Notley, Saskatchewan Premier Brad Wall and Calgary Mayor Naheed Nenshi.

NDP Leader Tom Mulcair, in contrast, celebrated Obama鈥檚 choice.

Trudeau said Friday morning in a statement that he is 鈥渄isappointed鈥� with the rejection, but that he is looking forward to 鈥渁 fresh start鈥� with Obama that will strengthen ties between the two countries.

鈥淭he Canada-U.S. relationship is much bigger than any one project,鈥� Trudeau said.

鈥淲e know that Canadians want a government that they can trust to protect the environment and grow the economy. The Government of Canada will work hand-in-hand with provinces, territories and like-minded countries to combat climate change, adapt to its impacts, and create the clean jobs of tomorrow,鈥� he added.

Obama said Friday that he spoke with Trudeau and the two leaders agreed that 鈥渙ur close friendship on a whole range of issues -- including energy and climate change -- should provide the basis for an even closer co-ordination between our countries going forward.鈥�

'A fait accompli': Ambrose

In a statement, Ambrose expressed 鈥渆xtreme disappointment,鈥� but also called it a 鈥渇ait acompli.鈥�

Ambrose pointed out that, in her view, 鈥渢he rejection of Keystone will not stop Canadian oil exports to the United States. It simply means we will continue to rely on transportation alternatives like shipping and rail.鈥�

The interim leader later pointed out that the U.S. Environmental Protection Agency had given its approval to the project, and the State Department had given conditional approval, so she agreed with former prime minister Stephen Harper that it was a 鈥渘o brainer.鈥�

Ambrose said that Obama鈥檚 鈥減olitical interference鈥� had created great 鈥渦ncertainty鈥� for 鈥渕arket access that is so incredibly important for our economic viability.鈥�

鈥淚鈥檓 from Alberta,鈥� Ambrose added. 鈥淔ifty-thousand people have lost their jobs in less than a year. This is tough news for Alberta, and this is tough for the energy sector.鈥�

鈥�(Obama) has been focused squarely on the Keystone XL pipeline as a symbolic gesture to his environmental legacy and his environmental supporters,鈥� Ambrose added, 鈥渨hen we know that there (have) been thousands of miles of pipeline built in the meantime.鈥�

Ambrose said that she spoke to Trudeau soon after the rejection and urged the prime minister to 鈥減lease continue to advocate for Keystone XL.鈥�

鈥淭he politics of Keystone continue to unfold and there may be an opportunity for the (U.S.) senate and (U.S.) congress to still intervene,鈥� she said, 鈥渟o I urged (Trudeau) to please work with me on opening up market access for our energy sector (and) he agreed to work with me on that.鈥�

Mulcair 鈥榲ery satisfied鈥�

NDP Leader Tom Mulcair told reporters in Vancouver that he is 鈥渧ery satisfied that president Obama has come to the same conclusion as us, which is that it鈥檚 not a good project.鈥�

鈥淎s we head into the Paris conference on climate change, it sends a strong signal that everybody鈥檚 taking these issues more seriously,鈥� Mulcair said.

Pipelines are 'low-emissions': Notley

Alberta Premier Rachel Notley echoed Ambrose鈥檚 comments about moving oil by rail

鈥淧ipelines are actually low-emissions ways to transport oil,鈥� she said. 鈥淩ail cars are not low-emission ways to transport oil.

鈥淲e need to be able to have careful drama-free conversations about the economics of our energy infrastructure,鈥� Notley added.

鈥淥ne of the ways we can help make that happen is for this government to do its part in ensuring that our commitment to combatting climate change is real.鈥�

Pipelines 'far safer' than rail: Wall

Saskatchewan Premier Brad Wall was also 鈥渄isappointed.鈥�

鈥淭his decision is more about U.S. domestic politics than it is about good environmental policy,鈥� Wall said in a written statement.

鈥淭he fact is pipelines are safer -- far safer than other means of transporting oil, like rail,鈥� Wall said, adding 鈥渢he equivalent of 10 Keystone XLs (have been) built in the U.S. since 2010.鈥�

Wall said that the decision means Energy East, a planned pipeline project from Alberta to New Brunswick, is 鈥渆ven more crucial and it will be one of Saskatchewan's top priorities as we begin our work with the new federal government.鈥�

Nenshi 'very disappointed'

Calgary Mayor Naheed Nenshi also expressed disappointment.

鈥淚 am very disappointed that one pipe, nearly a metre wide, is being asked to bear all the sins of the carbon economy,鈥� Nenshi said in a statement.

鈥淣onetheless, Canadian energy must have access to markets, and I will continue to partner with industry and other orders of government to advocate for other alternatives, of which there remain many viable options.鈥�

Dion: 'Our oil is clean'

Global Affairs Minister Stephane Dion the decision is disappointing, but also a reminder that Canada 鈥渘eeds to invest more in our ability to say to the United States and the rest of the world that our oil is clean and that we do our best to reduce our greenhouse gas emissions.鈥�

Dion said he disagreed with Obama鈥檚 comment that Canada鈥檚 oil is 鈥渄irty.鈥�

鈥淚 don鈥檛 think it鈥檚 accurate,鈥� Dion said. 鈥淚 don鈥檛 think our oil is so much emitting more than the other sources of emissions, but it鈥檚 true that we need to do more to not be vulnerable to this kind of criticism.鈥�

The minister said his government believes in the Energy East project, 鈥渂ut at the same time we want to do it properly (with) strong environmental assessments.鈥�

'Absolutely committed': CEO

Despite Obama鈥檚 rejection, TransCanada Corp. said it will review all of its options, including filing a new application for a Presidential Permit.

"TransCanada and its shippers remain absolutely committed to building this important energy infrastructure project," Russ Girling, TransCanada's president and chief executive officer,鈥� said in a news release.

"We will review our options to potentially file a new application for border-crossing authority to ship our customer's crude oil, and will now analyze the stated rationale for the denial."

Girling said TransCanada 鈥渃ontinues to have the support of American and Canadian workers, labour organizations, industry and most of all, the American and Canadian people.鈥�

'The right decision'

Environmental Defence, a vocal opponent of the Keystone XL project, welcomed Obama鈥檚 announcement Friday.

鈥淥bama鈥檚 rejection of Keystone XL demonstrates historic leadership by saying no to new fossil fuel infrastructure,鈥� the group鈥檚 climate and energy program manager, Adam Scott, said in a statement.

鈥淔or the first time, a pipeline has been rejected because it puts our climate at risk 鈥� a litmus test that the new Canadian government should adopt.鈥�

Scott said the rejection sets an important precedent just days before the climate change summit in Paris.

鈥淐anada鈥檚 newly-elected government must learn from President Obama鈥檚 rejection and rethink our failed economic strategy that has focused so heavily on exporting fossil fuels,鈥� he said.

Kenney: An 鈥渋nsulting decision鈥�

Potential Conservative leadership candidate Jason Kenney called the rejection 鈥渋nsulting鈥� on Twitter.