Amazon started laying off employees in its cloud computing and human resources divisions on Wednesday as it continues to trim down operations. 

Amazon Web Services CEO Adam Selipsky and Beth Galetti, senior vice president of people experience and technology, sent a letter to impacted staffers in U.S., Canada, and Costa Rica on Wednesday morning. 

"It is critical that we focus on identifying and putting our resources behind our top priorities—those things that matter most to customers and that will move the needle for our business," Selipsky wrote. "In many cases this means team members are shifting the projects, initiatives or teams on which they work; however, in other cases it has resulted in these role eliminations."

The move is part of Amazon's plan, announced in March, to cut 9,000 additional roles "mostly" in its cloud computing unit Amazon Web Services and PXT, which handles human resources, as well as its advertising and Twitch teams. 

CEO Andy Jassy announced the additional cuts after telling staffers in January that the company was going to cut 18,000 jobs, marking the largest round of layoffs in the company's history. 

The latest job cuts bring its total workforce reduction this year to 27,000 – a fraction of its overall global workforce of about 1.5 million.

This is a developing story. Check back for updates.