"At the end of this week, we will move into the new building," Timkin told reporters, adding that it will open next Tuesday.
The formal inauguration will take place on July 4, US Independence Day, and will be attended by former US President George Bush and German Chancellor Angela Merkel.
The Embassy has been rebuilt next to the Brandenburg Gate in what was once the no-man's land along the Berlin Wall. The old mission was bombed during World War II and its ruins razed to make place for the Wall.
Timken said the inauguration will be a celebration of US solidarity with Germans during the Cold War.
"This is a historic event, not simply turning the key to a new facility. For many years America stood at arms here in Berlin and elsewhere in Germany to protect freedom in this country," he said. "There's no better reason than returning here than to celebrate the victory of these values."
The new building cost €130 million ($202.5 million) to build and was delayed by a row with the city government over the extensive US security concerns following the terrorist attacks of September 11, 2001. Some Berlin official's were concerned the Americans wanted to build their own wall on the very place where East Germany's once stood.
Timken said the opening will also be attended by US pilots who took part in the Berlin Airlift 60 years ago when the Allies flew in tonnes of food and other supplies to West Berlin after it was blockaded by the Soviet Union.