Keane says the Red Devils must do everything possible to sign the England international even if it will cost them £120 million.
The 27-year-old’s future at the Tottenham Hotspur Stadium is currently up in the air as it has been reported that Kane is set to leave Spurs in search for another club.
Kane needs a project that matches his ambition of winning trophies and the North Londoners does not look like an option.
The Englishman’s current situation has put Tottenham’s Premier League rivals on alert with the likes of Manchester City and Chelsea all said to be monitoring the former Leicester City man’s situation.
Keane has urged Manchester United to join the competition and do whatever it takes to sign Kane.
“The only thing I’d hold against Kane, there’s a big negative I have towards Kane,” the 49-year-old told SkyBet.
“I think Kane is an amazing player, every club should be trying to sign him, Manchester United have got to sign him, I don’t care if it’s £120 million… sign him.
“But I don’t think he’s a good leader. I never see him digging anyone out at Spurs. I know people might go, ‘well that’s not his personality’ or, ‘he might do it in the dressing room’. I don’t think he does and that’s a big problem.
“Okay, you can lead with your brilliant play. But I think sometimes I want to see another side to Kane, I’d love to see him get hold of somebody.”