Statement by National Security Council Spokesperson Adrienne Watson
We've seen the reports out of Poland and are working with the Polish government to gather more information. Shortly after receiving these reports, National Security Advisor Jake Sullivan spoke with Chief of the National Security Bureau of Poland Jacek Siewiera.
We cannot confirm the reports or any of the details at this time. We will determine what happened and what the appropriate next steps would be.
Joseph R. Biden, Statement by National Security Council Spokesperson Adrienne Watson Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/358803