Secretary of State Hillary Clinton used an awards ceremony Sunday in Berlin to push European allies for greater cooperation in confronting extremism, nuclear proliferation and other challenges of the 21st century.

Her remarks came as thousands of people GERMANY/WALLcrowded into the city on the eve of the 20th anniversary of the collapse of the Berlin Wall.

“We should look to the examples of the generations who brought us successfully through the 20th century and once again together chart a clear and common course to safeguard our people and our planet, defeat violent extremists and prevent nuclear proliferation,” Clinton said.

“We need to form an even stronger partnership to bring down the walls of the 21st century and to confront those who hide behind them,” Clinton said, like suicide bombers and those who attack girls for trying to go to school.

“In place of these new walls, we must renew the trans-Atlantic alliance as a cornerstone of a global architecture of cooperation,” she said.