The gathering will be held in Warsaw on Wednesday.
During the meeting, Poland's Security Services Council will discuss "alleged Russian and Belarusian influence in the Polish power apparatus in previous years," Tusk said on the X social media platform on Tuesday.
A day earlier, authorities in Warsaw launched a spy probe after a Polish judge asked for political asylum in neighbouring Belarus.
Tusk told reporters on Tuesday that the judge, Tomasz Szmydt, "had access to various classified documents" and ties to Belarus.
"We must be aware that security services, in this case Belarusian ones, worked with a person who had direct access to the Minister of Justice ... who had access to various classified documents to which no intelligence service should have had access," Tusk said before a government meeting in the southern Polish city of Katowice on Tuesday.
He added: "The fact that judge Szmydt's relationship with Belarusians has a long history, that it is not a matter of recent months, must be a cause for deep concern."
Poland, a hub for Western military supplies to Ukraine amid Russia's invasion, is on heightened alert for any signs of spying activity, the Reuters news agency reported.
(gs)
Source: IAR, PAP, Reuters, polskieradio24.pl