They are aware of Sunderland’s huge reluctance to sell but intend to make life as difficult as possible for Black Cats owner Ellis Stafford and could raise the ante to £7 million.
Hammers boss Slaven Bilic is the driving force behind the move seeing the 34 year old as the ideal player to feed off Andy Carroll’s flick-ons in a 4-2-2.
With Diafra Sakho sidelined until early spring, after surgery, the manager knows he has to get Defoe or somebody like him in during January.
The club remain convinced that Defoe wants a return to the Irons following his departure nearly 13 years ago .
Defoe would be offered the remainder of the season and next and although the Hammers know the fee would be ‘dead money’ they are determined to invest in goals for the rest of the season of there is any chance of wooing Sunderland into selling