The Cottagers' 13-season stay in the top flight ended this season with a 19th-placed finish after using three managers.
The American billionaire said in the Evening Standard: "This is not about balancing the books
"I am committed and we are going to do whatever to get them back to the Premier League
It (relegation) is not what we wanted, but it is reality
What we have to do is build it for the long haul
"We are going to do whatever it takes to put the best team on the field
I have talked to Felix and what we want to do is what is in the best interest of the team."
Lewis Holtby believes the potential of the young players at Craven Cottage will help them respond to the drop
Germany midfielder Holtby had a limited impact on loan from Tottenham, playing 13 games, scoring once, but insisted he "cried with the club" when the Cottagers' demotion to the Championship was confirmed at Stoke.
"It was fantastic to play for this club and they will always stay in my memories," Holtby said on fulhamfc.com.
"Even though we went down I had a fantastic time here
I cried with the club when we went down and Fulham will always be a part of me.
"The fans took to me and I took to them
I'm a person who plays with passion and desire.
"When you play for a club, even on loan, you have to give 100 per cent dedication, you can't just go and take the money.
"You have to play football with heart and the Fulham fans deserve that."
Fulham reached the FA Youth Cup final, losing in agonising fashion to neighbours Chelsea, and Holtby believes youth can provide the foundation for future success.
"This club has a brilliant academy," he said.
"A fresh start can see a lot of young blood come in and that can only bode well for the future."
Source : PA