NEW YORK -- The New York Islanders are officially Brooklyn-bound.

The Islanders announced Wednesday that they've agreed to move from Long Island to Brooklyn's Barclays Center and share the $1 billion arena with the Nets.

"You don't have to worry about the future of this team," NHL commissioner Gary Bettman said at a news conference Wednesday. "It's remaining local."

The Islanders have established a 25-year agreement to play at Barclays Center beginning in the 2015-16 season. Their lease at Nassau Coliseum expires after the 2014-15 season.

Islanders owner Charles Wang said he plans to honor the existing lease and also plans on retaining 100 percent ownership of the team. Wang added that the 25-year agreement is "ironclad" when asked about a potential opt-out. The Islanders' team name and logo will not change.

"We are the New York Islanders," Wang said.

The announcement was made with Wang, Bettman, New York Mayor Michael Bloomberg, Brooklyn borough president Marty Markowitz, Islanders general manager Garth Snow, Barclays Center owner and developer Bruce Ratner, and Barclays Center and Brooklyn Nets chief executive Brett Yormark in attendance.

"Brooklyn is big-time and now we have the big league sports to prove it," Bloomberg said.

Ratner said Wang had "very good offers to move the team out of our state, very good offers, and Charles wouldn't do that."

Ratner later called Wang "a hero."

As of now, Barclays Center would only hold 14,500 for hockey, but Bettman says plans are in place to increase the attendance to "15,000-plus." At 15,004, Winnipeg's MTS Centre currently has the NHL's smallest capacity. Nassau Coliseum only seats 16,234, making it the second-smallest venue in terms of capacity.

"A thousand seats ... I don't think it makes a material difference," Bettman said. "It's not an issue."