In a memo to staff published by CNBC on Monday, Iger told employees that this week, management would begin notifying those whose positions would be cut as part of the restructuring he announced last month.

This would be the first of three waves of cuts, Iger said.

A second, larger round of notifications would take place in April that would result in several thousand more job reductions, and a third and final round of cuts was expected to go ahead in the summer.

By the end of the three lots of layoffs, Iger said Disney would have reached its target of trimming 7,000 jobs.

After detailing how the job cuts would be carried out, Iger thanked those who would be laid off for their “numerous contributions and devotion” to the entertainment giant.

“The difficult reality of many colleagues and friends leaving Disney is not something we take lightly,” he said. “This company is home to the most talented and dedicated employees in the world, and so many of you bring a lifelong passion for Disney to your work here. That’s part of what makes working at Disney so special. It also makes it all the more difficult to say goodbye to wonderful people we care about.”

He also conceded that for those who remained at the company, there would “no doubt be challenges ahead as we continue building the structures and functions that will enable us to be successful moving forward.”

“In tough moments, we must always do what is required to ensure Disney can continue delivering exceptional entertainment to audiences and guests around the world—now, and long into the future,” Iger said as he signed off in the memo.

Iger, who returned to the helm of the entertainment giant in November after just 11 months away from the company, announced in February that Disney would be laying off 7,000 workers as part of a plan to cut $5.5 billion in costs.

At the time, he said the strategy, which will also see Disney restructured into three core divisions, would better position the company to “weather future disruption and global economic challenges.”