Biden left Trump 'inspirational' message in 'very nice' letter, new president says

"It was a very nice letter," Trump told reporters. "It was a little bit of an inspirational-type letter. Enjoy it, do a good job. Important, very important. How important the job is."

The president added that he appreciated the letter so much that he may release it to the public.

"It was a positive, for him, in writing it," Trump continued. "I appreciated the letter."

"He may have. Don't they leave it in the desk? I don't know," Trump told Doocy before discovering the white envelope. "Thank you, Peter. It could have been years before we found this thing."

Trump had then teased reporters that they should read it together before pulling back the reins. He said he'd open the letter later Monday night.

Biden, however, was the first president to find himself in the unique position of writing a letter to someone who is both his successor and the predecessor who left him a note four years earlier. Trump became the first president to serve nonconsecutive terms since Grover Cleveland in the late 1800s.

Biden has said Trump left him a "very generous letter," but has so far declined to share the content of what Trump wrote, deeming it private.

Fox News Digital's Greg Wehner contributed to this report.