WarnerMedia is the latest corporate entity to put new focus on employee travel as the coronavirus continues to spread around the world.

In a memo sent to staffers Monday, Jeff Zucker, chairman of WarnerMedia’s news and sports operations, said employees may need to get permission to travel, and indicated that he would personally have to approve travel between continents, which would be “limited to only the most necessary, business-critical need.”

CNN will cover such national events as the Democratic debates and Turner Sports will broadcast coverage of NBA games and the coming NCAA men’s basketball championship, Zucker said in the memo. But there will also be a new level of caution. “We will work to be sure that our staffing needs are met, but limit any participants that are not absolutely critical to getting our content out or meeting basic revenue-generating needs,” he said. “Some of this can be determined simply by using good judgment, and we encourage you to consider your travel with that in mind.”

Zucker indicated in his memo that employees of all WarnerMedia operations were being given new travel guidelines. CNN will continue to staff ongoing national coverage, he said, but “with the same considerations taken about limiting the travelers to those who absolutely need to be there.”

“Nothing is more important than your well-being. While some of these protocols may seem inconvenient, they are being taken out of an abundance of caution to keep you all safe,” Zucker said.” It is unclear how long these restrictions will remain in place, but we will continue to communicate regularly as the situation both domestically and globally changes.”