Mandaric added: "I'm bitterly disappointed. The only thing we can get out of this is to become a stronger club going forward, stay united and re-organise ourselves and build a strong base.
"If people trust me I will always come through for them and I think this will be the same."
The Foxes lost their Championship status on Sunday after a goalless draw against Premier League-bound Stoke.
Mandaric stated: "If I said I didn't have regrets I would be lying to you. You don't have to be Einstein to figure out we are in the business of results and the results aren't there.
"We have see what was done right and wrong, correct it quickly and immediately and go forward to win games and show Leicester City in a new colour."