The UK is making a "serious push" for better cross-border co-operation to fight organised crime.

The Attorney General, Lord Goldsmith, has told a conference in London governments must work more closely to fight drug trafficking, people smuggling and money laundering.

Criminals don't respect borders - they exploit borders

Lord Goldsmith

He urged the seventh annual International Association of Prosecutors' conference to build on the progress that has been made in the past 12 months.

"There are prosecutions taking place now which I believe might not have happened if we had not had an enhanced spirit of co-operation since 11 September," said the minister.

"We have all been taught a hard lesson about how much more we can do if only we have the will to do it.

"The experience of the last 12 months demands that we come together in the fight against organised crime."

'Exploiting borders'

Earlier, Lord Goldsmith told BBC Radio 4's Today programme law enforcement agencies were at a disadvantage to the criminals.

"Crimes cross borders. Criminals don't respect borders. They exploit borders," he said.

"National enforcement agencies do have to respect borders because law enforcement takes place on a national basis.

"That's why we have to co-operate with each other.... so that we can get at these people."

Lord Goldsmith said he would be using the IAF conference to make a "serious push" for more co-operation.

He urged delegates to adopt a new plan of action, which he dubbed The London Plan, to improve international crime-fighting.

The plan includes the creation of a network of specialist prosecutors throughout the world backed up by new guidelines and legislation.

'Bumper harvest'

Moves to increase cross-border law enforcement have increased since the 11 September terrorist attacks on the United States.

Six European Union countries have pledged to introduce a Europe-wide arrest warrant by the start of next year - a year ahead of schedule.

Drug smuggling remains the biggest problem for international law-enforcers.

Earlier this year, Foreign Secretary Jack Straw announced that almost a third of Afghanistan's poppy fields had been destroyed.

But an investigation by BBC Radio 4's Today programme found there was little evidence that the crops were being eradicated.

And a bumper harvest suggests an increased amount of the drug on its way to the UK, where 90% of heroin originates in Afghanistan.

Director of Public Prosecutions, Sir David Calvert-Smith QC, will also address the IAP conference, which lasts until Friday.