National Public Radio is planning significant cost cuts as the coronavirus pandemic hits sponsorship and donation revenue, the public broadcaster's chief executive, John Lansing, said in a memo to staff.

NPR is facing a budget deficit of between $30 million and $45 million through its 2021 fiscal year, Mr. Lansing said in the Wednesday memo.

Sponsorship money is drying up amid "a very tough marketplace," he wrote, and donations could also take a hit as foundations and individuals "will be thinking hard about gifts as they watch the swings in the values of their own portfolios."

NPR will need to cut costs substantially, he wrote. The network's discretionary spending is under review, including new hiring, travel, conferences, promotions, bonuses and raises.

NPR is trying to avoid cutting jobs. "We do not have any position eliminations on the table now, and it is our goal to avoid them as much as is reasonably possible," Mr. Lansing wrote. "However, I don't have a crystal ball so I can't guarantee anything other than that is my intent."

Across the media landscape, TV networks, newspapers, digital publishers and radio outlets are all facing similar problems as advertisers slash ad spending during the crisis.

"NPR is taking a significant budget hit because of the economic lockdown due to the Covid-19 pandemic," NPR said in a statement. "We do not have a profit motive or shareholders to serve like commercial media, so all of our resources go toward public service."

"We will continue to manage our budgets closely across the organization -- our main priority is to preserve jobs. During this pandemic and beyond, NPR will continue to provide an essential public service to audiences across platforms," it said.

NPR, based in Washington, D.C., has a unique model. It is partially funded by the government-supported Corporation for Public Broadcasting, but generates much of its revenue from dues and fees paid by its many member stations. Member stations also are under financial stress, Mr. Lansing wrote.

NPR said that, on average, about 33% of its revenue came from corporate sponsorships from 2015 to 2019.

"Other news organizations are taking some drastic steps right now to deal with their finances," Mr. Lansing wrote. "They need to return profits to investors. We don't. But we do need to survive financially, and ensure NPR can continue to serve stations and the public for the coming years, so all of our resources go toward public service."

New York Times media columnist Ben Smith earlier tweeted about the NPR memo.

Write to Benjamin Mullin at Benjamin.Mullin@wsj.com