The 30-year-old Jubilo Iwata striker has been in London to train with the Hammers who are currently flying high in England's second tier following their relegation from the Premier League last season.
It is believed that West Ham boss Sam Allardyce has promised to give Maeda an answer by the start of next week on whether or not he will be offered a two-year deal that could be worth as much as US$1.9million a year.
"He's a player with a proven track record," Allardyce was quoted as saying by the Daily Mail.
"I have to decide if he can play a part in the team quickly."
Maeda bagged 14 goals in 28 J-League appearances last season, and helped Japan win a fourth AFC Asian Cup title in 2011.
"It might be a bit late to be taking on the challenge of playing abroad," Maeda, who was the J-League Golden Boot winner in 2009 and 2010, said.
"However, I hope to grow into a better player in Europe and bring that to the national team.
"At my age, this is likely my last chance to play overseas and I want to everything possible to make it happen."
News of Maeda's potential move, comes only days after it was confirmed that another Japan international in the shape of Tadanari Lee will be joining Southampton.