West Ham United have had a £6 million bid rejected by Sunderland for striker Jermain Defoe, sources close to both clubs have told ESPN FC.
West Ham are looking to bolster their attacking options and have targeted the striker, who used to play for the club between 1999-2004.
Slaven Bilic's side have struggled for goals this season, and currently find themselves in 13th spot in the Premier League table.
The summer loan signings of Simone Zaza and Jonathan Calleri have not been in good form since joining the club, while Andy Carroll has just recently returned from a lengthy spell on the sidelines and Diafra Sakho is out for several more weeks after picking up another injury just two games into his comeback from a long-term back problem.
Zaza seems set to return to Italy this month, clearing the way for West Ham to bring in a new forward, and Defoe has emerged as West Ham's top target to solve their goal scoring problems, with the former England international netting 11 goals in a struggling Sunderland side this term.
Sunderland have rejected West Ham's offer for Defoe and are not welcoming any further interest in the 34-year-old as they know how vital the striker is to their chances of avoiding relegation this season.
Sources have told ESPN FC that West Ham are not optimistic over their chances of persuading the club to cash-in on Defoe despite the Black Cats' lack of funds to bring in new signings this January.
Indeed, Sunderland boss David Moyes is determined to keep Defoe whatever West Ham offer as he feels the striker offers them their best chance of staying up this season.