The federal environment minister is urging Saskatchewan to sign on to Ottawa's national climate change plan or risk losing its share of federal money for emission-reduction programs.

Environment Minister Catherine McKenna took aim on Twitter at the only province not to sign on to a framework on clean growth and climate change as the deadline loomed.

"I am simply encouraging Saskatchewan to sign on to our national climate plan," McKenna said Wednesday in an interview with The Canadian Press. "Every other province and territory has signed on to it," she said.

"If Saskatchewan signs on ... we will be able to partner with them. We have $62 million that could be used for energy efficiency programs in Saskatchewan."

That money would come from a low-carbon fund for projects that make buildings more energy efficient or that store or capture carbon during agricultural activities.

Saskatchewan Premier Scott Moe wasn't available for comment, but said in Regina on Tuesday that he won't sign on to the framework because it comes with an "ill-conceived" carbon tax. The province has threatened in the past to challenge the plan in court.

Moe said Saskatchewan will still apply for its share of the money from the low-carbon fund.

"We require that investment to continue to lower the emissions here in the province of Saskatchewan," he said. "We have some aggressive targets here ... that we intend on meeting, in particular around our power generation.

McKenna said signing on to the framework is a requirement for provinces to get the money, so Saskatchewan will forfeit its share if it doesn't do so.

Saskatchewan's money would go back into a fund that cities, First Nations, businesses and farmers who want to reduce emissions would have access to.

"It would be an unfortunate signal that Saskatchewan isn't working with all of the rest of the provinces and territories and the government of Canada to tackle climate change," said McKenna.

"We need to meet our international obligations and we have a huge economic opportunity -- in the trillions of dollars -- to move toward clean growth."

McKenna said the federal government will move forward with the plan, including a carbon tax, by the end of the year -- with or without Saskatchewan.

"We've been clear that provinces and territories that don't put a price on pollution, or don't put a price on pollution that meets our benchmark, that the federal government will step in. All revenues will go back into the province."