The Daily Mail says the Hammers are trying to sign Mbokani on a five month loan deal.
The Congo international only joined Monaco from Standard Liege for £7million in the summer but has struggled to settle and is keen to kickstart his career with a switch to the Premier League. However, the problem could be obtaining a work permit.
Although Congo have a wealth of talent, and club side TP Mazembe reached the final of the Club World Cup against Inter Milan, the country is ranked a lowly 124th in the world and West Ham may have to go to an appeal.
Everton have monitored the 25-year-old for the past 18 months and may yet launch their own bid to sign him if other targets fall through but West Ham are in the driving seat.