Twitter will tell employees by email on Friday about whether they have been laid off, temporarily closing its offices and preventing staff access, following a week of uncertainty about the company's future under new owner Elon Musk.

The social media company said in an email to staff that it will alert employees by 9 a.m. Pacific time on Friday (12 p.m. EDT/1600 GMT) about staff cuts.

"In an effort to place Twitter on a healthy path, we will go through the difficult process of reducing our global workforce on Friday," said the email, seen by Reuters.

Twitter said its offices will be temporarily closed and all badge access will be suspended in order "to help ensure the safety of each employee as well as Twitter systems and customer data."

The social media platform said Twitter employees who are not affected by the layoffs will be notified via their work email addresses.

Staff who have been laid off will be notified with next steps to their personal email addresses, the memo said.

The notification of layoffs caps off a week of purges by Musk as he demanded deep cost cuts and imposed an aggressive new work ethic across the social media company.

He had already cleared out the company's senior ranks, firing its chief executive and top finance and legal executives. Others, including those sitting atop the company's advertising, marketing and human resources divisions, departed throughout the past week.

The layoffs, which were long expected, have chilled Twitter's famously open corporate culture that has been revered by its employees.

Shortly after the email landed in Twitter employee inboxes, hundreds of people flooded the company's Slack channels to say goodbye, two employees told Reuters. Someone invited Musk to join the channel, the sources said.

"If you are in an office or on your way to an office, please return home," Twitter said in the email on Thursday.

Musk has also directed Twitter Inc's teams to find up to $1 billion in annual infrastructure cost savings, according to two sources familiar with the matter and an internal Slack message reviewed by Reuters.