"Speaking with one voice is what makes Europe strong," Merkel said in a speech addressing the German Council on Foreign Relations in Berlin on Wednesday.

The German chancellor said she would like to see more constructive debates and less quarreling during the six-month German EU presidency, starting on Jan. 1, 2007. This will be a challenge both with inner-European issues such as the question of constitutional reforms, and in the realm of foreign policy.

Merkel said that Turkey would face consequences if Ankara failed to open its ports to ships and planes from Cyprus as part of a bid to join the European Union.

"Turkey must fulfill its obligations by the end of the year," Merkel said. "Otherwise the EU will draw the appropriate conclusions."

The German leader underlined that a continuation of Ankara's present ban on ships and aircraft from EU member state Cyprus was out of the question.

The remarks came as the European Union on Wednesday gave Turkey a mid-December deadline to open its ports to Greek Cypriot vessels, saying this was a key condition for keeping Ankara's EU entry bid on track.

Kosovo: a sensitive topic

Merkel stressed that negotiations about the future status of Kosovo will be of central importance for the EU.

"What should happen by no means is that we stabilize one part, but for the price of destabilizing other parts," Merkel said.

"The relationship to Serbia is complex and it can effect Macedonia and Bosnia and Herzegovina. That is why we need to approach this with utmost sensitivity without bringing the process to a halt," she said.

The Serbian parliament officially adopted the country's new constitution on Wednesday reiterating Serbia's claim over Kosovo, offering wide autonomy but ruling out possible independence for the province largely populated by ethnic Albanians.

Keeping the gas flowing

Another important aspect of the EU foreign policy will be the relationship to Russia, one of Europe's most important trade partners and energy suppliers.

Merkel said that a new cooperation and partnership agreement with Russia should have its energy chapter "formulated with clear basic rules."

"Russia is at the moment not ready to ratify the transit protocol of the Energy Charter Treaty," Merkel said. "We would like to see that happen."

The Energy Charter Treaty -- an international agreement which was signed in 1994 together with a protocol on energy efficiency with the aim of integrating western and eastern European energy markets -- would give European companies wider access to Russian gas and oil fields and to the Russian energy market. Russia, however, remains wary of foreign companies tapping into the country's energy sources.

"Many eyes will be directed towards Germany as far as wider responsibility in the world is concerned," Merkel said. "And we will not be able to shun this responsibility."