Uruguay will begin selling cannabis in pharmacies from July, the final stage in the country's pioneering regularisation of the drug.

The South American country will be the first in the world to legally sell the drug over the counter for recreational use.

The move was set in motion in 2013 with a law that fully legalised the cannabis trade.

However, it has been a slow process to put the law into practice.

"Cannabis will be dispensed in pharmacies starting in the month of July," presidential aide Juan Andres Roballo told a press conference.

The law requires buyers to sign up to a national registry, which Mr Roballo said would be up and running by 2 May. The price will be US$1.30 (£1) per gram.

Registrants - who must be Uruguayan citizens or permanent residents - can purchase up to a maximum of 40 grams (1.4 ounces) per month.

The marijuana sold will come from state-supervised fields.

The law also allows users to grow their own at home, or join cooperative clubs that farm it.

Many pharmacists have doubted the financial benefits of selling a cost-controlled product.

Some Uruguayan buyers were also reluctant to sign up to a national registry, complaining of the invasion of their privacy and of having to keep to the monthly limits.

The government has now done a deal with 16 pharmacies, but it hopes to sign up more.

Mr Roballo said there would be a public health campaign before the registry was opened.

He also said the government was not close to covering the predicted demand, but it does not believe there will be "an avalanche of users" signing up,