I prefer to concentrate on my task of leading Europe to the success that our citizens expect. We have to look forwards now because what is at stake is what makes Europe Europe.

The good thing about the European Union is that the joint project ultimately benefits all Member States and not just a few.

Trump knows that he is encountering a complete lack of understanding in Europe, but it's apparent that he's not very impressed by it. My experience, however, has been that American presidents take a greater interest in Europe over the course of their term.

Now it is firstly a matter of a clean divorce, because citizens and companies need legal certainty. Can there be a new partnership with the United Kingdom one day? All 27 Member States would have to agree to that. And the United Kingdom would first have to reflect on what it wants itself.

Decisions can only be reached in Europe if France and Germany agree.

I would describe that [friendship with Greek Prime Minister Alexis Tsipras] as a utilitarian friendship. At the time, his country was facing the prospect of leaving the euro zone and many Greeks felt abandoned by Europe. In such a situation, it seemed appropriate to me to present myself as a friend to Greece. It had to do with the country's dignity.

Trump is a partner for us who cannot be easily categorized. Putting it in the noblest way possible, his understanding of politics is a little different from ours here in Europe. The way he acts forces us Europeans to take on a new responsibility. We are not standing with our backs up against the wall, but, to put it as pithily as the German chancellor has: We can no longer rely on the U.S. the way we could in the past.