In a letter in Sports Illustrated in mid-July, James announced he was leaving the Miami Heat for a return to the Cavaliers.
Durant, speaking after training with Team USA, said he congratulated the 29-year-old following the announcement.
"It was classy. It was a great move to do it as a letter," Durant said.
"That was pretty cool. It's funny seeing guys think about more than just basketball for once.
"He thought about the city where he comes from, about Northeast Ohio and how he can affect so many of the kids just being there playing basketball. I love that.
"So many guys get criticised for making the decision that's best for them, instead of what's best for everybody else. He's a guy that did that. You've got to respect that."
Durant, who has two years remaining with the Oklahoma City Thunder, only said he would do "what is best" for him when his contract expires.
Now a team-mate of James', Kyrie Irving said the signing was an indication the Cavaliers were heading in the right direction.
"We all suspected it would happen," he said.
"We didn't know until it really happened, I found out when everyone else found out so, I mean, it was a surprise but more of an exciting turn.
"The organisation is going in the right direction and the essay that he wrote obviously spoke volumes about what he wants to accomplish and I want to be a part of that as well so hopefully we can make something special happen in the next few years that we're together."