He kicked off his visit by sitting down for talks with German Chancellor Angela Merkel.

Her spokesman describes the talks as wide-ranging and "very open," covering issues ranging from Iran and Afghanistan to the global economy, climate and energy. And he says Merkel and Obama stressed the "great significance of close and friendly German-American relations."

This evening, Obama delivers what could be a centerpiece of the trip, an address in front of Berlin's 226-foot-high Victory Column. It's expected some 100,000 people will hear what Obama's campaign calls a "substantive address on U.S.-European relations."

Germany is the first European stop on Obama's nine-day overseas trip. He goes next to France and Britain.