The papal conclave to elect the successor to Pope Benedict XVI, who will step down on Feb. 28, could begin prior to March 15 if all the cardinal electors are in Rome before that date, Vatican Press Office Director Federico Lombardi said Saturday.

He said that under the Holy See's constitution the conclave should begin between 15 and 20 after the papacy becomes vacant to give time for all of the cardinals to arrive in Rome.

But if all of them arrive before that amount of time has elapsed, the conclave can be moved up, Lombardi said, adding that more information will be provided in the coming days.

He also reiterated that the pope will travel on Feb. 28 to the papal summer residence in Castel Gandolfo, some 30 kilometers (18 miles) from Rome, and will stay there until restoration work has been completed on a monastery within the Vatican that will serve as his retirement home.

Lombardi added that the pope's personal secretary and prefect of the Pontifical Household, Archbishop Georg Gaenswein, told him Saturday that he has noted a sense of serenity in Pope Benedict even though the days since his stunning resignation announcement last Monday have been emotionally draining and hectic.

He will be the first pope to resign in nearly 600 years. EFE