NHL commissioner Gary Bettman toured the renovated Nassau Coliseum Tuesday to assess the improvements needed for the arena to host Islanders games while the team’s new home at Belmont Park is being built. Nassau County Executive Laura Curran, Islanders co-owner Jon Ledecky, Brooklyn Sports & Entertainment CEO Brett Yormark and Long Island Association CEO Kevin Law also were in attendance. A source said there was a 30-minute meeting followed by a 90-minute tour of the facility. The NHL, Islanders, Brooklyn Sports & Entertainment and Curran’s spokesman confirmed the meeting took place but all declined further comment. In December, Gov. Andrew M. Cuomo announced that a development team led by the Islanders will invest $1 billion in private funds to transform Belmont Park into a state-of-the-art sports and entertainment destination, including construction of an 18,000-seat arena that will bring the hockey club permanently back to Long Island. The Islanders and Barclays Center are in the process of opting out of their lease agreement. Ledecky has said the Islanders plan to play the 2018-19 season in Brooklyn, as per the team’s arena lease. Sources familiar with the negotiations said the two sides are discussing playing some Islanders games at Nassau Coliseum as early as next season.