Plans to redevelop the club's ground and increase the capacity from 37,645 seats to approximately 53,000 were approved in January by Leeds City Council.
Australian billionaire Lowy told BBC Leeds: "Leeds is ready for it.
"If we don't get it done this time, it will never happen.
"It does need to be done in a timely manner though because people like myself and the capital that we have won't sit around for 10 years because we can invest wherever we choose to invest."
Lowy also said: "We are doing all the pre-work with the city, just like we did on the stadium, for a masterplan for the area, and last week Leeds Council approved a masterplan that we've been working with them on.
"We have the ability, if the transportation system is there, to build 2,500 housing units, maybe 200,000 square feet of offices, local retail, fresh food markets.
"What we need is the political class to get its act together. We don't get any pushback from government at the moment but they need to get aligned and get their job done."