The Hammers are in talks with Sporting Lisbon over the transfer of Portugal international William Carvalho. The Euro 2016 winner has a £40m release clause in his contract and has scored nine goals in 137 appearances for the Portuguese club.
When asked if the club were any closer to signing the 25-year-old, Bilic said: "Nothing new. I am not frustrated. It is a position we have been trying to do that (strengthen) for a couple of seasons now. We need someone to boost our team, quality and everything.
"We need that position and that is why we have offloaded some players to get the budget for him. I am not talking about the player (Carvalho), I am talking about the player for that position. The quality player not the quantity one. It is not easy to get them but we are doing our best."
Bilic says he is looking to bring quality rather than quantity to his squad and if he is unable to secure his first choice target he will not look elsewhere.
"I think you say OK, no problem we have good players," Bilic added. "We are not talking about the quantity, we are not talking about boosting our squad. We are talking about boosting our game. It is impossible to find many of them in our case."
Carvalho has previously been linked with moves to Manchester United and Arsenal and the Angolan-born midfielder played a key role in the Portugal side which won the European Championships in France last summer.