"I just went to the Oval Office and found this beautiful letter from President Obama," Trump said. "It was really very nice of him to do that. And we will cherish that. We will keep that."
He ended the moment with a tease of the media.
"And we won't even tell the press what's in that letter," he said.
The good-bye letter from president to president has turned into a staple of the transition of power. Traditionally, it's a page-long message that bridges partisanship and instead carries a personal and poignant message of well-wishing.
Trump in the ceremony then went on to praise the members of his staff before Vice President Mike Pence administered an oath of office. This included top advisers such as Kellyanne Conway, Steve Bannon and his son-in-law Jared Kushner, whose appointment to a senior staff position has raised questions among ethics lawyers about a potential breach of nepotism law.
In Trump's tribute to his staff he also offered a hint of early confidence at a successful run in 2020.
"And speaking of important, you are very important because with you and all of the people in this room, we are going to do some great things over the next eight years," Trump said.