The figures, in line with expectations, indicate the state's recreational pot stores did about $14m (€10m) in gross sales for the month.

Colorado legalised cannabis in 2012, but commercial sales did not begin until January with the opening of two dozen recreational pot shops.

The tax figures intensified lobbying over how Colorado should spend the money

Governor John Hickenlooper, who opposed the legalisation of recreational cannabis, would like to see the bulk of state revenue derived from both recreational and medical pot sales to go toward addiction treatment and programmes to prevent youths from using the drug.

He wants, for example, more advertising discouraging driving while high.

Under federal law, cannabis is still illegal, but the US government has indicated it will not act against states that have legalised it.

Washington state sales begin in coming months.

Other countries also are watching Colorado, which has the world's first fully regulated recreational marijuana market.

The Netherlands has legal sales of pot but does not allow growing or distribution. Uruguay's marijuana programme is still under development.