Russian and Belarusian boxers will be removed from the WBC rankings and banned from competing for titles under the sanctioning body's authority.
The WBC initially announced it would not sanction any boxing in Russia the day after the country's invasion of Ukraine on February 24 this year.
But at the sanctioning body's convention in Mexico on Tuesday, WBC president Mauricio Sulaiman announced boxers from both Russia and Belarus would be removed from their rankings due to the ongoing conflict.
"All fighters from Russia and Belarus are being removed from the WBC rankings," Sulaiman said.
"The WBC will not sanction any fights in those two countries and no national citizen from those two countries can compete for a WBC championship title.
"I wish to express our deep regret for the athletes, for the promoters, for the members of the boxing industry from Russia and Belarus who will suffer with these consequences of the actions outside the ring.
"The WBC believes in peace, believes in fair play, and believes human dignity."