This is according to the diplomatic mission's website, Ukrinform reports.
"Out of an abundance of caution, the Embassy will be closed, and Embassy employees are being instructed to shelter in place," the statement said.
The U.S. Embassy recommended U.S. citizens be prepared to immediately shelter in the event an air alert is announced.
The embassy did not provide any details about the possible strike.
U.S. citizens were advised to monitor local media for updates; identify shelter locations in advance of any air alert; immediately take shelter if an air alert is announced; and follow the directions of Ukrainian officials and first responders in the event of an emergency.