The Kennedy Center announced Thursday that it has raised an additional $40 million in gifts for its campus expansion project, set to break ground late next year.

Though still in the design phase, the $100 million privately funded expansion will provide an additional 60,000 square feet of indoor space, an outdoor video wall for simulcast performances, and landscaped gardens and public space.

To date, the Kennedy Center has raised just over 70 percent of its target goal of $125 million, with a lead gift of $50 million from David Rubenstein announced in January. The capital campaign target includes $25 million to fund upcoming programming, including the Washington National Opera’s production of Wagner’s Ring cycle, which is scheduled for 2016.

Michael Neidorff, treasurer of the Kennedy Center and co-chair of the capital campaign, said that this second phase of giving included gifts from 10 to 12 donors. Neidorff and his wife, Noémi, pledged “multiple millions” as the lead pledge, but the center is not yet releasing donor names or specific figures from this round of funding.

As for whether the center is meeting its fundraising targets, Neidorff said,“We’ve had aggressive expectations, plus or minus 5 to 10 percent,” he said. “We hope to complete [the fundraising] in the late first half or early second half of next year.”

Steven Holl Architects is designing the expansion project. The Kennedy Center expects construction will be completed by 2017.