Newly elected Pope Benedict XVI has celebrated his first Mass as pontiff, pledging to work to unify all Christians and continue "an open and sincere" dialogue with other religions.

Pope Benedict XVI
The former Cardinal Joseph Ratzinger delivered the message Wednesday, in Latin, to the cardinals who elected him less than 24 hours earlier in the Vatican's Sistine Chapel.

The 78-year old German-born pontiff said he felt a sense of inadequacy after his election on the second day of the papal conclave. But he said he felt his predecessor, the late Pope John Paul II, was "holding his hand."

The new pope also confirmed he will attend World Youth Day festivities in Cologne, Germany this August.

The official inaugural Mass for Pope Benedict -- the 265th leader of the Roman Catholic Church -- is set for Sunday , April 24, in Saint Peter's Square.

Some information for this report provided by AP and Reuters.