Ibrahimovic is available on a free transfer after his contract was not renewed by United following a serious knee injury suffered in April.
Jose Mourinho and United have hinted the 35-year-old – who scored 28 goals in all competitions as the Manchester side won the Europa League and EFL Cup last season – may return to Old Trafford in 2017-18.
But the Galaxy are ready to welcome Ibrahimovic to LA, with Klein telling reporters: "We have an incredible relationship with Zlatan and his agent. He loves our club, and he loves LA.
"We have an interest in him. I think, for now, he wants to stay in Europe.
"Our doors are open for a player like that. We have rights to him in our league. We'll see where that goes."
This week, the Galaxy signed Mexico international Jonathan dos Santos from Villarreal and replaced head coach Curt Onalfo with Sigi Schmid.