Starbucks CEO Brian Niccol said the coffee chain is committed to bargaining in good faith with the union that represents many of its baristas, as the two sides work to craft a labor deal.

“I deeply respect the right of partners to choose, through a fair and democratic process, to be represented by a union,” Niccol wrote on Tuesday in a letter to the union obtained by CNBC. “If our partners choose to be represented, I am committed to making sure we engage constructively and in good faith with the union and the partners it represents.”

He was responding to a letter from the Starbucks Workers United bargaining delegation sent a day earlier, ahead of another bargaining session between Starbucks and the union. The two sides are negotiating a framework that would be the basis for collective bargaining agreements between individual stores and the company. The union is pushing for fair scheduling, a living wage, and racial and gender equity, the delegation said in its letter.

“We know that many of your dedicated customers — as well as future generations of customers — have a vested interest in the outcome of our negotiations and reaching a foundational agreement,” the group wrote in its letter to Niccol.

Three years ago, Starbucks baristas started unionizing under Workers United, an affiliate of the Service Employees International Union. For two and a half years, the coffee giant tried to curb the union push, leading to battles that played out in headlines, social media and courts.

But the turning point for both parties came six months ago when they agreed to work together on a path forward after mediation to resolve lawsuits sparked by the union’s posts on social media.

Niccol joined Starbucks several weeks ago, making him a newcomer to the union discussions. In his previous role as CEO of Chipotle Mexican Grill, only one location, in Lansing, Michigan, successfully unionized. Last year, the burrito chain agreed to pay former employees of an Augusta, Maine, location $240,000 as part of a settlement for closing the restaurant when workers tried to unionize. Chipotle denied any wrongdoing.

Today, Workers United represents more than 490 of Starbucks’ U.S. cafes and more than 10,500 of its employees. The company has more than 16,700 locations in the U.S., more than half of which are owned by the company.