Irish leader Enda Kenny and President Michael D Higgins led tributes to Pope Benedict XVI after he announced his retirement on Monday.

The Pontiff, 85, is to leave on February 28 due to ill health. He is the first Pope to resign in almost 600 years .

“After having repeatedly examined my conscience before God, 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,” Benedict said in a statement.

Irish political and religious leaders were among those who paid tribute to the 265th Pope.

"On behalf of the Government and people of Ireland, I would like to extend best wishes to His Holiness Pope Benedict XVI following his declaration today that he intends to step down from his office," Kenny said.

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"This is clearly a decision which the Holy Father has taken following careful consideration and deep prayer and reflection.”

President Higgins said he had written to the Pope expressing his good wishes on his decision to retire.

"In his letter, President Higgins acknowledged the scholarship and personal commitment that Pope Benedict brought to his leadership of the Roman Catholic community over the past eight years and wished him every peace and fulfilment in his retirement," the president's office said in a statement.

Cardinal Sean Brady described his decision to step down as as humble and responsible.

"I think it is a profound act of humility, a conscientious and responsible decision to hand over the ministry of the successor of Peter at a time of great challenge in the church and for faith in the modern world," he said.

Archbishop of Dublin Diarmuid Martin said the Pope's decision to resign was courageous. "Who knows how long he has to live? Only himself and his advisers know that," Archbishop Martin said. "But to do this, shows he has that interior freedom within himself."

In New York, Cardinal Timothy Dolan said Monday that he was startled by Pope Benedict’s resignation.

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In an official statement, Dolan said: "We are sad that he will be resigning but grateful for his eight years of selfless leadership as successor of St. Peter. He delighted our beloved United States of America when he visited Washington and New York in 2008. As a favored statesman he greeted notables at the White House. As a spiritual leader he led the Catholic community in prayer at Nationals Park, Yankee Stadium and St. Patrick's Cathedral. As a pastor feeling pain in a stirring, private meeting at the Vatican nunciature in Washington, he brought a listening heart to victims of sexual abuse by clerics."

The Vatican says it expects a new Pope to be elected before Easter.

A look back at Pope Benedict XVI's career:

Pope Benedict XVI has announced his retirement due to ill healthGoogle Images