Story highlights

NEW: The Chicago teacher's union chief says '"we've still got big issues"

The teachers union has authorized a strike for Monday

The school board president describes Saturday's talks as "productive," but not conclusive

Chicago has the nation's third-largest public school system

CNN  — 

Despite what the head of Chicago’s school board deemed a day of “productive talks,” the nation’s third-largest public school system entered Sunday without a contract with teachers – and with a strike looming.

Teachers and support staff in Chicago set a walkout date Monday, which would mark the first time they have gone on strike in 25 years.

Speaking late Saturday, Chicago Teachers Union chief Karen Lewis said that no action has been taken to alter the teacher’s plans not to work next week.

“We’ve made some progress, but we’ve still got big issues on the items we’ve always had big issues on,” she told reporters, shortly after walking out of union headquarters with a group singing “solidarity forever.”

About 40 minutes earlier, the president of Chicago’s board of education told reporters progress was made in extensive talks Saturday, while noting the pressure posed by the fast approaching deadline.

“We’ve got parents and children who are wondering what’s going to happen to them Monday morning,” said David Vitale. “We have an obligation to them to tell them what’s going to happen. And we really want to get this work done.”

If a strike happens, it would affect nearly 700 schools and about 400,000 students, including some from neighborhoods struggling with crime and gang problems.

For them, that would mean the school year would abruptly stop not longer after it started: Some students in the district began class on August 13, and more – on a different schedule – started on September 4.

Vitale said the school system presented the union with an “updated proposal,” from one submitted Thursday, on Saturday that takes into account the union’s concerns on issues such as compensation, merit pay and health care.

“We have moved dramatically on almost all these issues to try to accommodate them and to respect our teachers,” Vitale said, noting that there have been “well over 100 meetings” over eight months of talks. “This is a proposal that we believe is very close to what is needed to do a deal.”

Lewis, from the teachers union, said that she wouldn’t characterize the school system’s movement as “dramatic,” saying only “they are starting to talk about the … issues that we are most concerned about” like compensation, benefits and job security.

The union could act swiftly to cancel the planned strike, though there are currently no plans to do so, the union president said.

The two sides will return to the negotiating table at 11 a.m. Sunday, according to Lewis. She declined to offer any predictions on what will happen and whether a strike will be averted.

Vitale, on the other hand, said he was “still optimistic that our children will be in school on Monday morning.”

“We have high hopes that we can get back to tomorrow, we can move to the end game,” he said.