The England international has spent the last six months at the San Siro after protracted talks saw the Galaxy relent on their initial desire to see him go back in March.
Fresh speculation has suggested Beckham will now try to stay at Milan over the summer but Beckham said: "The only thing certain at the moment is that in July I will return to play with the Los Angeles Galaxy and I will meet my current (AC Milan) team-mates in a friendly."
He added: "I respect the Los Angeles Galaxy and I have a mission to accomplish.
"I want to promote football in the United States. It's possible that I will return in January to play for Milan but there are still some factors to clarify.
"Before I arrived here, they warned me that I would remain fascinated by Milan and they were right."
Former Manchester United and Real Madrid star Beckham has been a huge hit in Italy.
But he admits a deal to keep him at the Rossoneri would likely prove too tricky to negotiate.
"In life nothing is certain, but I believe it's a complicated path," Beckham said.
"In order to remain three further months at AC Milan, I had to make many financial sacrifices. It's not a decision that you can take from one day to the next in your living room."