The German capital is the first stop on a whirlwind tour that will take Obama to Germany, France and Britain in an effort to burnish his foreign credentials as he campaigns against Republican Sen. John McCain for the US presidency.

While in Berlin, Obama will meet with German leaders, including Chancellor Angela Merkel and Foreign Minister Frank-Walter Steinmeier.

He will cap his day with an open-air speech before an expected crowd of at least 100,000 that his campaign has described as a "substantive address on US-European relations."

The address has symbolic value because several US presidents - including John F. Kennedy, Ronald Reagan and Bill Clinton - made significant addresses in Berlin.

Former German President Richard von Weizsaecker said that the Obama event could help pave the way for a new trans-Atlantic relationship, according to a newspaper report.

"Kennedy said the famous sentence: 'Ich bin ein Berliner' - Obama could send the Berlin signal: America is counting on Europe for its future," he was quoted as saying by the Bild newspaper Thursday.

"We have long believed that nobody in America is interested in our continent any more," he said in further quotes attributed to him. "The appearance and the speech of Barack Obama are evidence that this preconception is false."

After landing at Tegel Airport, his aircraft taxied beside the soon-to-depart plane of Iraqi Prime Minister Nouri al-Maliki, who visited Berlin this week for talks aimed at luring German companies to invest in his country.

Obama met with al-Maliki in Baghdad earlier this week during the Middle East part of his tour.