Heroin accounted for nearly a third of the total number of drug-related deaths in Britain in 2005, the last year for which statistics are available, the government said.
Cowper-Coles said that Britain doesn't have any significant policy differences in Afghanistan with the US, although Britain does not back Washington's interest in launching an aerial spray campaign.
"There are occasionally differences of emphasis," he said. "We're both agreed that there's no case for aerial spraying unless the government of Afghanistan agrees to it, and as I understand it the government of Afghanistan does not favor spraying."