The Hammers have not made many significant additions to the squad that finished sixth in the Premier League last season and qualified for the Europa League.
They have only brought in goalkeeper Alphonse Areola on loan from Paris Saint-Germain this summer, despite Moyes wanting to add more players to his squad.
The West Ham manager wants to sign a centre-back and a forward before the end of the transfer window.
But with eleven days left in the window, there is no significant movement on incomings at West Ham at the moment.
Moyes insisted that the club are working hard behind the scenes to further strengthen the squad but conceded that he cannot give any guarantees that new players will come in before the window closes.
He does though remain hopeful that something can be done.
The West Ham boss said in a press conference: “Yeah, I do [hope to bring in more players]. I hope to do some more business.
“We have been trying hard and we are trying to add to a good group of players.
“We have a challenging season ahead of us and I am hoping we can do something but we have no guarantees.”
West Ham opened their season with a 4-2 win over Newcastle last weekend and will host Leicester City at the London Stadium on Monday night.
