EDMONTON -- Canada's premiers say the federal government needs to more fully answer questions surrounding the legalization of cannabis or they will need more time to get their rules in place.

Alberta Premier Rachel Notley told the closing news conference at the leaders' annual summer meeting in Edmonton that there are five areas that need to be clarified.

They include road safety and enforcement, preparation and training on distribution, taxation, public education, and supply and demand and how that might affect the black market.

"Premiers around this table agreed that should the federal government not engage adequately on these issues, we will need more time to implement the federal government's decision," Notley said Wednesday.

Ottawa has said it will pass legislation to make recreational pot legal next July 1, but it will be up to the provinces to decide on details such as how it will be distributed and sold, where it will be allowed and what the minimum buyer's age should be.

Notley did not suggest how much of a delay the provinces might be seeking.

"We'll work to the deadline, but as things stand right now, there is work that also needs to be done by the federal government in order for us to meet it. It has not yet been done."

The premiers have struck a working group to seek answers from Ottawa and to provide recommendations by November on how to move forward.

Manitoba Premier Brian Pallister suggested Tuesday that the unanswered questions require the law be delayed by one year. He did not reference that timeline at the closing news conference, but described the task of cannabis legalization as a "monumental undertaking."

He said all the leaders have concerns about legalized cannabis that need to be addressed and "we have one chance to get it right."

"The prime minister wants to stick to his deadline. That's super-duper," Pallister said. "He needs to then hear what the premiers of his country, our country, have said we need help with."

Prime Minister Justin Trudeau was asked at a stop in Quebec City if there is any flexibility to the July 1 deadline. He replied that the goal is still to have the law passed by next summer.

He said right now young people have easy access to marijuana when they shouldn't and criminals and streets gangs are making millions through illegal sales.

"We need to put an end to this policy that does not work," Trudeau said.

"We are continuing to work with the provinces to make sure the framework will be in place a soon as possible."