Pope Benedict XVI on Monday announced that he will resign due to his old age and lack of strength to govern the Church, an announcement marked as the first in the modern history of the Catholic Church.

Pope Benedict XVI on Monday announced that he will resign due to his old age and lack of strength to govern the Church, an announcement marked as the first in the modern history of the Catholic Church.

The German-born pope said he would step down on February 28, which will make him the first pontiff to resign in centuries.

"I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of the Petrine ministry," the 85-year-old pope said in a speech delivered in Latin at a meeting of cardinals in the Vatican.

Reading from a written text, the pope made the announcement in a hall in his residence, the Apostolic Palace next to St Peter's Square.

Vatican spokesman Federico Lombardi said he expected a conclave of cardinals to be held in March within 15 or 20 days of the resignation and a new pope would be elected before Easter Sunday on March 31.

In response to the announcement, German Chancellor Angela Merkel said she had the "greatest respect" for the Pope’s decision.

For his part, French President Francois Hollande said “the Pope's decision was "eminently respectable".

British Prime Minister David Cameron said the pope had worked "tirelessly" to boost ties with Britain.