Ibrahimovic was keen to join Galaxy at the end of his PSG tenure in the summer of 2016, but the proposed switch fell through and he ended up penning a one-year deal at United.
"It was supposed to happen before Manchester United. My head was here. I wanted to come here and it didn't happen," said Ibrahimovic.
"These things sometimes go like that. But my destiny said I was going to come here, Los Angeles called and I answered."
The Swede could make his debut against Los Angeles FC.
"I'm available. I have so much adrenaline in me, so I think I can last a long time."