US presidential candidate Barack Obama called in Berlin on Thursday for stronger ties across the Atlantic Ocean.

Obama made the call in his speech in front of the 226-foot high Victory Column, his first formal speech outside the United States.

German Foreign Minister Frank-Walter Steinmeier (L) and US Democratic presidential candidate Senator Barack Obama meet members of the media in Berlin July 24, 2008. (Xinhua/Reuters Photo) 

"The walls between old allies on either side of the Atlantic cannot stand," Obama said, winning applause from over 100,000 crowds standing on the street the Berlin Wall once ran over.

The Illinois Senator urged Europe and the United States to work together to "defeat terror and dry up the well of extremism that supports it."

US Democratic presidential candidate Senator Barack Obama is surrounded by Secret Service agents as he boards an elevator at his hotel in Berlin, July 24, 2008. (Xinhua/Reuters Photo) 

"The walls between the countries with the most and those with the least cannot stand. The walls between races and tribes, natives and immigrants, Christian and Muslim and Jew cannot stand," he said.