Pope Benedict XVI's decision to step down from his office was made soon after his trip to Mexico and Cuba in March 2012, according to a senior communications officer at the Vatican.

"What's interesting is how long ago this decision was made, shortly after the Pope's trip to Cuba, which was in March of last year," said Vatican advisor Greg Burke.

On Feb. 11, Pope Benedict XVI announced to a gathering of cardinals in Rome that he no longer has the strength to carry out the office of the papacy and will resign on Feb. 28. He is 85 years of age.

Burke confirmed that the decision was made months ago, after a six-day trip during which the pontiff was described as visibly tired and speaking with a strained voice.

Burke's comments countered media rumors that the decision to retire was tied to the scandal of Pope Benedict's one-time butler, Paolo Gabriele, who stole confidential Vatican documents and leaked them to the media. The decision in March "was before the whole butler story even broke," Burke observed.

His statement echoed the comments of Vatican spokesman Father Federico Lombardi, who explained at a recent press conference that "the trip to Cuba and Mexico, due to his fatigue, was another reason in the development of Benedict XVI's decision, but not its cause," according to the Vatican Information Service.

"He did not resign the pontificate because he is ill, but because of the fragility that comes with old age," Fr. Lombardi stressed.

The Vatican spokesman also acknowledged that the Pope has had a pacemaker for years and recently underwent surgery to replace the batteries in the device, although he said that this procedure "had no impact on his decision."

Father Georg Ratzinger, the brother of Pope Benedict, has told reporters that the pontiff was advised by his doctor months ago not to make further transatlantic trips.

The decision has been a long-time coming, Burke noted.

"We should have all paid a lot more attention to the fact that the Pope prayed not once, but twice before the tomb of Celestine V. He obviously knew what Celestine was feeling when he stepped down," the analyst observed.

Saint Celestine V became the first Pope to resign from the position in 1294. Pope Benedict visited the saint's relics twice during his papacy. In 2009, he prayed at the tomb and left his own pallium on top of it. And again in 2010, he visited the cathedral of Sulmona to visit the relics of St. Celestine and pray before his predecessor.

Burke also affirmed that there will be no problem of "competing popes" after the pontiff's resignation goes into effect on Feb. 28.

He explained that "if Pope Benedict still wanted to have influence, he wouldn't have stepped down."