The United States offered Tuesday to help Denmark put an end to a gang war that has raged in Copenhagen for more than a year and has left seven dead and dozens of innocent bystanders injured.

- We have some expertise in the area of gangs ... And if we can offer some assistance or training that would be beneficial, we would be happy to do that - US Secretary of Homeland Security Janet Napolitano told reporters after meeting with Danish Justice Minister Brian Mikkelsen.

Among other things, the two ministers discussed the Danish gang war that has pitted motorcycle gangs against youths of immigrant origin in a battle over the drugs market since the summer of 2008.

Mikkelsen said he would welcome any assistance from the United States.

- We are going to have a series of meetings with the Americans to take advantage of their advice and we plan to carry out a research project to find out why some urban neighbourhoods are more affected than others by gang crime - he said.

Denmark also hopes to learn from the US' experience in fighting youth criminality.

Napolitano's visit to Copenhagen was part of a European tour aimed at combatting human trafficking.