A Danish soldier was killed by an explosive device while on patrol in southern Afghanistan, the Danish defence ministry said on Thursday.

"A Danish soldier from Task Force 7 lost his life on the night between Wednesday and Thursday in the Helmand province of Afghanistan during a patrol with Afghan security forces," it said in a statement.

The incident took place in the west of the volatile province, near the town of Gereshk.

A ministry spokesman said 43 Danish soldiers had died since international forces were deployed in Afghanistan in late 2001. Denmark currently has around 700 troops in the country.

NATO combat forces are to pull out of Afghanistan by the end of 2014. By then, the coalition is aiming to train 350,000 Afghan soldiers and police to take over responsibility for security.

But trust between the two sides has been seriously undermined by "insider" attacks by Afghan forces that killed more than 60 foreign troops in 2012, and the transition process has been beset by other problems including desertions.