President Trump said Monday he is concerned about the suspected plague case in Russia, saying the U.S. is “looking at it very strongly.”The State Department said Monday it was monitoring the suspected case of pneumonic plague in Irkutsk Oblast, Russia.

“I hate to see them having it,” Trump told reporters before departing the White House for Nebraska.

“It’s a rough disease. We used to be able to control, but somehow those microbes have gotten stronger and smarter.”

“The germs have really become relatively stronger than they were, and things that used to work on pneumonia don’t work as well anymore,” he said.

Pneumonic plague “is a rare and often fatal disease that can be transmitted by respiratory droplets from animals or persons infected with Yersinia pestis bacteria,” according to the Centers for Disease Control and Prevention. It is different from pneumonia, which is the term for inflammation of the lungs.

NBC News reported Monday that some 200 people were under medical observation in Siberia after a 28-year-old lab worker, who was possibly exposed to the pneumonic plague, died.

On Sunday, the Russian consumer welfare service said the 28-year-old, who worked at an institute combating the plague in Irkutsk, died from “pneumonia of unknown etiology,” the outlet reported. Trump said Monday “we’ll help” Russia with the potential outbreak. A State Department official said Russia has not provided many details on the issue. “Many details have not been confirmed. We encourage Russian authorities to share accurate information quickly and openly,” the official said.

“Plague is a known disease and is treatable with common antibiotics, especially when treatment starts early. Cases occur naturally in many parts of the world.”