"Frustrated is an understatement in the amount of deals we've tried to do in the last six to eight weeks," West Ham's Twitter account quotes Allardyce as saying.
"There are very few deals happening across the board at the moment because it's difficult to get the right players at this time.
"Later in this window things generally get a bit easier in financial terms, in that clubs want to move the players on. That's why you get a flood of deals in the last few days of the window. Our need is to produce a really good signing that can hit the ground running and have an impact right away."
The Hammers are currently 18th in the Premier League table after 22 games.