The man known as 'Mbazo' captained the South African national team at the 2010 World Cup and his performances in the yellow and green seem to have attracted suitors from the Premier League, Turkey and Qatar.
Mokoena told The Sowetan that although he feels a strong affinity towards Pompey, he could be tempted to leave Fratton Park - with the South African newspaper claiming the Hammers and Trotters are eager to land his services
"I have to confess my heart is still there at Portsmouth and they are offering me a new contract if I remain with the club," he said.
"I can confirm that there are a number of offers from several big clubs - three in the English Premiership, two in Qatar and one in Turkey."
The 29-year-old utility man, who can play in defence and in midfield, claims he is still evaluating his options and said he will make a decision in the near future.
"There are a number of things I am still assessing, though and I will decide sometime next week," he said.
Should Mokoena complete a switch to Upton Park, he would reunite with his countryman Benni McCarthy, with whom he played with at Ajax and Blackburn while West Ham's new manager, Avram Grant, was in charge of Pompey last season.