"The responses to international terrorism have not always been adequate" despite a broad consensus among the nations of Europe and the United States about the danger, he told an anti-terrorism conference in Werder, 50 kilometers (31 miles) southwest of Berlin.

Schäuble was joined by US Homeland Security Secretary Michael Chertoff and the interior ministers of France, Britain, Italy, Spain and Poland for the two-day meeting, which ended Saturday.

The talks were designed to explore ways of strengthening preventive measures against terrorist actions and improve methods of cross-border coordination in combating terrorism.

Extraditing terror suspects

The German minister said different solutions were needed because the penalties enshrined in criminal laws in force today no longer acted as a deterrent to terrorists.

One of the issues under discussion was how to deal with terrorist suspects holding foreign passports -- more specifically whether they should be extradited if the countries receiving them pledge to treat them according to international law and human rights standards.

Another issue covers the exchange of information related to terrorist threats and the legal aspects covering how such information is obtained.

Search for common principles

Experts from the seven participating countries were also present at the conference, which did not pass any resolutions.

The aim of the gathering was to lay the foundation for a long-term process by which the different states can agree on common principles on how to deal with terrorism, Schäuble said.