"The FIM, IRTA and Dorna Sports regret to announce the postponement of the Gran Premio d'Italia Oakley (May 31) and Gran Premi Monster Energy de Catalunya (June 7)," MotoGP said in a statement.
"The ongoing coronavirus outbreak has obliged the two events to be rescheduled.
"As the situation remains in a state of constant evolution, new dates for these GPs as well as the recently postponed French and Spanish GPs, cannot be confirmed until it becomes clearer when exactly it will be possible to hold the events."
MotoGP added that a revised calendar will be published "as soon as available."
The German Grand Prix on June 21 is the next scheduled race in the calendar. (Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Hugh Lawson)