President Barack Obama tells a Nevada radio audience to beware of Donald Trump.

“The main thing I’m trying to emphasize to people is if you don’t vote, that’s a vote for Trump,” he said during an interview on the Zenja Dunn Show on 105.7, calling it a “stark choice” in the upcoming election.

Obama said that Trump wasn’t “fit for office” and lacked not only the temperament but the political background or the policies that were required to serve as president.

He warned that if Trump was elected, many of the advances he made as president would be lost.

“If you don’t vote, that’s a vote for reversing the policies that have gotten us out of the worst recession in our lifetime,” he said. “If you don’t vote, you’re voting for a much more unstable world.”

A recent poll showed that Hillary Clinton is only leading Trump in Nevada by three points, even thought the state went overwhelmingly for Obama in 2008 and 2012.