The Whites, three-time champions of England, have not graced the top flight since they were relegated in 2004, just three years after playing in the Champions League semi-finals.
The Yorkshire side's malaise even included a three-season stint in League One, but United manager Warnock has recently seen his club taken over by Bahrain-based firm GFH Capital and says Leeds are now in a position to regain their place in the elite division.
"Leeds are one of biggest clubs I've managed in my life and one of the top six in the country," said the 64-year-old, who took the reins at Elland Road after Simon Grayson was sacked in February 2012.
"All clubs have periods where they go down and come back up but I think we have changed everything in the last 12 months; the squad is better and steadier and the club is in a good financial state.
"The new owners are doing things in the right way; they not spending £40milllion but instead having a good look around and will then probably invest in the summer. I don't think we need too much - though I do want to bring one or two in.
"Plus, our fans fill out away grounds and the way they support us is unbelievable, so whether we go up this year or not, in the next 18 months Leeds will become a Premier League club again."
United currently lie in a mid-table spot in the Championship but Warnock is refusing to rule out their hopes of gate-crashing the top six following an improved run of form that has yielded wins over Blackpool and Millwall and a draw at Leicester.
However, the erstwhile Notts County and Sheffield United manager says he will depart Elland Road if he does not guide Leeds into the Premier League - though he hopes that will not signal the end of his footballing career.
"We were disappointed to concede a last-minute equaliser against Leicester in midweek, but I said to the lads a few weeks ago that we need to go and enjoy it and since then have played with a bit more freedom," said Warnock, who took QPR into the top flight in 2011.
"If we don't get promotion I will call it a day, though, becuase my family is in Cornwall and I want to spend time with them before I lose my faculties and my health.
"However, I do feel that there is a role for experienced managers between the board of directors and the manager; I don't think we use ex-managers enough and I would quite like a role that (Crawley director of football) Steve Coppell has."