"Tough decisions" need to be made to address the growing number of Nashville schools in the state's bottom 5 percent, the school board chair said Monday, and she did not rule out closing some low performers.

Nashville's share of the state's lowest performing "priority schools" has grown sharply. Six Metro Nashville Public Schools sites fell in the bottom 5 percent in 2012, compared to 21 in the latest round of data released Friday.

At an event scheduled to address the latest round of state priority schools, district officials largely cast the trend as an issue of inadequate funding. Sharon Gentry, the board chair, said the district would have to be open to closures as one way to shift money and other resources where they are needed.

"We can't take it off the table," Gentry said. "We're going to have to be prepared as a board, as a central office, to make tough decisions to free up the limited resources we have so that we can provide the best for all of our children."

Many of the newly identified priority schools are under capacity. A district spokeswoman said officials were researching enrollment trends at schools that are under capacity, although she said no decisions had been made.

Nashville school distinct leaders said Monday they will get at least $3.6 million in added federal funding to support the 21 low-performing schools.

But, they said, that won't meet their needs.

"I'm sure it's not enough," said Metro Nashville Public Schools Director Shawn Joseph said during an event addressing the growing number of district schools that fall in the state's bottom 5 percent.

More special funding for the priority schools is expected from the state in the next month. The most recent state budget allocated $10 million for grants to priority schools.

Joseph did not say how much more was needed, but he said the district still expected to see improvements even without additional funding.

"We're just going to get them a lot slower," he said. "To accelerate you'll need an accelerant."

Joseph said his administration will zero in on four areas to improve schools: school leadership, effective instruction, growing talent, and student and family support systems.

At the event, they didn't elaborate on the tactics they would use in to accomplish their goals. But they said community partnerships would be key, especially in addressing issues outside of school like poverty, unemployment and affordable housing.

Reach Adam Tamburin at 615-726-5986 and atamburin@tennessean.com. Follow him on Twitter @tamburintweets.