By Oana Lungescu BBC European regional correspondent

Drug use is increasing in member and candidate countries

A new study says that the expansion of the European Union could lead to increased drug use and trafficking across the continent, but could also provide an opportunity for better co-ordination in tackling the drugs problem.

In its annual report, the EU drug monitoring agency warns that some countries set to join the union next year are threatened by what it describes as the most rapidly developing HIV epidemic in the world.

Most member countries are showing signs of increased drug use, it adds.

Almost every day border police across eastern Europe seize large quantities of heroin and other drugs, more easily available in the region after the collapse of communism.

National strategies

The report highlights the alarming increase in HIV infections in two future member states - Estonia and Latvia - where more than 10% of injecting drug users are infected with the virus.

But it also notes that Europeans are getting better at working together to tackle the drug problem.

According to the agency, all future EU members have developed national drug strategies, although many projects, such as syringe and needle-exchanges, remain controversial and underfunded.

The report shows that all existing EU countries are concerned about rising cocaine use in big cities, especially in Britain, Denmark and Germany.