Canada's Senate has given final passage to the federal government's bill to legalise recreational cannabis, though Canadians will have to wait at least a few months to legally buy marijuana.

Prime Minister Justin Trudeau's government had hoped to make pot legal by July 1, but the government has said provincial and territorial governments will need eight to 12 weeks following Senate passage and royal assent to prepare for retail sales.

Trudeau's Cabinet is expected to decide a legalisation date in early or mid-September.

The law makes Canada the second country to have a nationwide, legal marijuana market, after Uruguay. Each province in Canada is coming up with rules for the sale of recreational pot.

The bill passed in the Senate by a vote of 52-29 on Tuesday.