The Swedish striker has previously signed two deals at Old Trafford.
His initial spell proved to be a resounding success, as he netted 28 times in all competitions – including match-winning efforts in the Community Shield and EFL Cup final.
An untimely injury brought his 2016-17 campaign to a close, but he was handed fresh terms by United the following season after returning to fitness.
The enigmatic frontman has been a revelation in America, netting 22 times in 26 appearances.
That form has sparked talk of a possible return to Europe over the winter, with former employers in Manchester and Milan said to be keen.
Ibrahimovic has been reluctant to be drawn on such speculation, but was happy to discuss a potential switch to West Ham while appearing on The Late Late Show hosted by Hammers fan James Corden.
He said: "I'm here with my buddy James and he wants me to come to West Ham.
"But they could not afford me. Let's put up the viewers for the James Corden Show first."
Corden responded by saying: "It's happening. We'll figure it out. We'll get the ball in the box with you on the end... done. Come on you Irons."
West Ham have been short of goals so far this season, netting just eight times in 10 Premier League fixtures.
Manchester United have fared a little better, finding the target on 15 occasions to date, but questions are being asked of Romelu Lukaku and his value to the Red Devils’ cause.
Alexis Sanchez is also struggling, while Marcus Rashford and Anthony Martial lack consistency amid regular spells on the bench.
Ibrahimovic has been mooted as a possible answer to those attacking posers, but the 37-year-old is giving little away when it comes to his future plans.