Obama, who is the chief guest at India's 66th Republic Day parade, laid a wreath at Mahatma Gandhi's memorial at Rajghat and planted a sapling in the complex on the bank of the Yamuna river.
Accompanied by Minister in waiting Piyush Goyal and Rajghat officials, Obama placed the wreath and paid floral tributes at the memorial of the apostle of peace.
He also observed a moment of silence and went around the black granite platform, which has Mahatma Gandhi's last words 'Hey Ram' inscribed on it. The entire complex, including the platform, was decked with flowers.
Obama, who is here on a three-day visit and has often invoked the legacy of Mahatma Gandhi and described him as an "inspirational figure", then signed the guest book.
The US president was presented a bust of Father of the Nation and seven points of his social messages. He then planted a sapling of 'peepal' tree in the complex of Gandhi memorial.