Thirty-year-old Dempsey spent five and a half seasons at Craven Cottage before moving on to Tottenham in summer 2012, and after a difficult year at White Hart Lane he decamped to the American Major Soccer League, joining the Seattle Sounders on a four-year deal in August.
But Dempsey has played the best football of his career for Fulham, and Klinsmann is convinced the forward's two-month loan return to his old club can prime him for this summer's big test with the US in Brazil.
"Obviously, we are pleased with Clint Dempsey, our captain, making the jump for two months to Fulham to get games in now," Klinsmann said.
"He had a very difficult couple of months because of injury and the transition back into MLS.
"I think it's a great decision from Clint to start off the year in the right way going on loan for two months to Fulham, his old team.
"They need him to get them back up in the table of the league, and he will come already in good shape back into MLS. That is great!"
Former Germany striker Klinsmann added on the US federation website, ussoccer.com: "Hopefully now he gets games with Fulham and then he comes in completely different shape back to MLS and continues that path towards the World Cup."