BUFFALO, N.Y. -- The Buffalo Bills will be playing in a new stadium within the next five or six years. Whether that stadium is in western New York or elsewhere remains to be seen.

The team's 10-year lease at Highmark Stadium expires in 2023 and negotiations between Erie County, which owns and operates the stadium, and the state of New York and Pegula Sports and Entertainment are ongoing for a new one. Bills owners Kim and Terry Pegula aren't interested in spending their own money on a county-owned stadium and say Highmark Stadium is not worth renovating. The county wants a fair deal and the state wants to keep the team in western New York.

On Monday, Speaking at Jim Kelly's celebrity golf tournament, NFL commissioner Roger Goodell made it clear the league wants to keep the Bills in Buffalo -- but in a new stadium.

"This has been going on for decades," Goodell said, "and it's time to get a new stadium done that we can make sure the Bills are here and successful for many, many decades going forward."

Here's what you need to know as the sides work toward a deal:

Why do the Bills want a new stadium?

Built in 1973, Highmark Stadium is one of the oldest stadiums in the NFL, and perhaps more problematic, it is outdated to a point where renovating and upgrading it would not be cost-effective. Despite the county-funded $227 million worth of renovations under the Bills' current lease, the cost to modernize the stadium would be roughly $1 billion. Jim Wilkinson, a spokesperson for Pegula Sports & Entertainment, told WKBW-TV in Buffalo any talks on renovating Highmark Stadium are "over."

"The stadium has a lot of problems," he told WKBW. "It's 50 years old and an independent engineering study says the upper deck is going to have to be replaced -- $500 million, the electrical will have to be replaced, the water systems have to be replaced, the ring wall is in jeopardy."

Erie County has not commented on the possibility of renovating the stadium.

Where would the new stadium be located?

The Pegulas want the Bills' next stadium to be built across the street from its current site in Orchard Park, New York. Wilkinson told Buffalo television station WIVB-TV the location makes the most sense considering its proximity to the team's training facility, which shares a lot with Highmark Stadium. Buffalo mayor Byron Brown publicly expressed his desire for a downtown stadium, where the team's original stadium -- War Memorial Stadium, which opened in 1937 -- was located until it was demolished in 1989, but Wilkinson effectively put those rumors to rest.

How much would the Bills' new stadium cost?

PSE's most recent proposal calls for a $1.4 billion stadium that PSE president Ron Raccuia told The Associated Press would be funded by "some sort of public-private partnership." The Buffalo News initially reported the Pegulas requested the stadium be 100% taxpayer-funded, which Erie County executive Mark Poloncarz insisted would not happen.

"We will get a deal done," Poloncarz said. "It's just got to be a fair deal for all."

The exact split is not yet known as negotiations continue, but Poloncarz said there would be no "blank check" written from Erie County.

Could the team be forced to play in a temporary location while the stadium is built?

It's possible, but it's unclear where the team would play if it had to use an alternate site during construction of a new stadium. The Bills played eight games in Toronto -- six in the regular season and two in the preseason -- from 2008 to 2013.

Could the Bills relocate if they can't agree to a stadium deal?

Could they? Yes. Just ask Oakland, St. Louis and San Diego if it's possible to lose an NFL team. But will they? It's unlikely since the Pegulas built an $18 million training center and purchased the team in 2014 under a strict no-relocation clause under its current lease at Highmark Stadium. Poloncarz said there was no threat by the Pegulas to relocate the Bills, but Wilkinson suggested the ball is now in the court of Erie County and the state.

"The Pegulas have made a proposal. They would like to build it right there [in Orchard Park] and we need to hear back," Wilkinson said. "You can't really do plans and designs on things until you have a deal, and right now the city of Buffalo and the state are going to have to decide if they want a team."

The Buffalo News reported the Bills suggested there are "other cities elsewhere that desire an NFL franchise and would pay handsomely for it." And in January 2020 during his state-of-the-league news conference before Super Bowl LIV, Goodell said Toronto "could be a great city for an NFL team," but "a stadium that is up to NFL standards is going to be a certain requirement."

Fans in western New York shouldn't overreact to the possibility of the team moving -- it's a negotiating tactic other professional sports franchises have used when trying to get a stadium. This isn't even the first time the Bills have used such a tactic. In 1971, former team owner Ralph Wilson told officials in Seattle that he was "very serious" about moving the team unless the city of Buffalo closed on a deal to build a stadium. His threat worked, and the Bills were playing in what is now Highmark Stadium two years later.