The Al Hasawi family, the Reds' Kuwaiti owners, have bankrolled nine new arrivals this summer at a cost thought to be in the region of £5 million.
Forest are known to have had further bids for two long-term targets rejected on Monday - Wolves forward Bakary Sako and Middlesbrough midfielder Grant Leadbitter - but Al Hasawi revealed the club also failed in their attempts to sign two other players.
Reacting to the disappointment, Al Hasawi pledged that the search for further new additions would resume when the loan window opens next week.
He said via a statement on the club's official website: "I would like to take this opportunity to inform our supporters that we attempted to sign four players in a bid to further bolster our squad.
"Regrettably, the value of each player rose over the course of the day to a point where we no longer considered any of our targets as suitable signings at this time.
"This should not detract from the work we carried out earlier in the window. A lot of money has been invested and I am delighted with the nine players we have brought to the club this summer. The early additions have allowed us to make an excellent start to what I'm sure will be a very memorable campaign.
"We will now turn our attention to the loan market before having another major push in the January transfer window.
"I will of course keep you informed of any developments."
Forest have recouped some of their outlay this summer with the sale of midfielder Adlene Guedioura to Crystal Palace. The deal, which is thought to see the Algeria international move for a fee of £2.5 million, was agreed on Monday night but was not completed until Tuesday.
- Sports & Recreation
- Bakary Sako
- Grant Leadbitter