US praises Germany's 'exemplary leadership' in Europe

Earlier in the day, when speaking to American and German students, he recalled how he cycled through the divided German capital shortly after the World War II had ended. His father, an American diplomat, had been posted to Germany at the time. He was not very happy about his son wandering about town and possibly creating a diplomatic incident, so he grounded Kerry.

"What you’re doing now in Germany is so remarkable in terms of leading Europe and expressing a vision about where we can go together," Kerry told the young audience.

He repeated the compliment when meeting Merkel, thanking "Germany's exemplary leadership."

Germany has been under strong criticism in southern European countries for its "austerity diktat," with protesters in Greece recently portraying Merkel as a Nazi.

Last week, the President of Germany, Joachim Gauck, said he was "shocked" to see those images and reassured troubled euro-countries Germany does not want to impose a "diktat" on Europe.

During his meetings in Berlin, with Merkel, young people and the foreign minister of Germany, Guido Westerwelle, Kerry also underlined the importance of signing a free trade agreement between the US and the EU.

“We want to see even more trade and investment that will create jobs, jobs for Germans, jobs for Americans, jobs for all Europeans,” he said in a joint press conference with Westerwelle.

The trade deal will help raise standards for products and food all across the world and break tariff barriers, he added.

"One of the difficulties with the Asian marketplace has been that they’re engaged in capitalism and they’re pursuing pretty intensive market opportunities, but they’re not always playing by the same rules," Kerry said.

When the US and the EU combine their markets and have common standards on products in such a large marketplace, Asia and other parts of the world will have to "raise their rules and standards" as well, he noted.

He said the harmonisation process will be "tough."

"There are differences of regulations on certain kinds of things. There are differences on agriculture policies. We have to work through those. I’m confident we can," he told German and American students.

Later on Tuesday, Kerry also met the Russian foreign minister, Sergei Lavrov, for almost two hours of talks about Syria.

The US foreign secretary is continuing his European trip with stops in Paris and Rome, after visiting London on Monday. Brussels, the EU capital, is not on his agenda, however.