Pope Benedict XVI is stepping down on Feb. 28 because of health concerns and age, the Vatican announced Monday.

The decision by Benedict, formerly Cardinal Joseph Ratzinger, makes him the first pope in six centuries to resign.

"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 his announcement.

In recent years, opinions from the Catholic Church's leaders sometimes conflicted with the agendas of U.S. president. In 2003, Benedict criticized the President George W. Bush's handling of the war in Iraq.

Benedict also disagreed with President Obama on abortion rights. Obama supports abortion rights for women, while the Catholic Church is staunchly opposed to the practice. The church under Benedict also opposed provisions about contraceptives in the Obama administration's healthcare law.

Benedict made his views on contraception and abortion known to other high-ranking politicians. In 2009 Benedict met with then-House Speaker Nancy Pelosi (D-Calif.), who is Catholic and one of the most vocal abortion rights supporters in Congress. Benedict urged Pelosi to make a "just system of laws capable of protecting human life at all stages of its development," a clear reference to abortion.

Still, Benedict did find common ground with the American political leaders. He and Obama shared the same view on nuclear proliferation, supporting reduction of the total number of nuclear weapons around the world.

After Obama was reelected, Benedict sent the president a message congratulating him.

Benedict reportedly said that he hoped Obama would serve "in respect of the essential human and spiritual values and the promotion of the culture of life and freedom of religion, which have always been so precious in the traditions of the American people and their culture," according to Reuters.

In a statement on Monday, President Obama recalled meeting with Benedict in 2009.

"On behalf of Americans everywhere, Michelle and I wish to extend our appreciation and prayers to His Holiness Pope Benedict XVI," Obama said in a statement. "Michelle and I warmly remember our meeting with the Holy Father in 2009, and I have appreciated our work together over these last four years.

“The Church plays a critical role in the United States and the world, and I wish the best to those who will soon gather to choose His Holiness Pope Benedict XVI’s successor," Obama added.

Speaker John BoehnerJohn Andrew BoehnerFreedom Caucus bruised but unbowed in GOP primary fights GOP revolts multiply against retiring Ryan Can Jim Jordan become top House Republican? MORE (R-Ohio) issued a statement praising Benedict's "steady leadership" of the Catholic Church.

"The prayers and gratitude of American Catholics are with Pope Benedict XVI today. The Holy Father's decision displays extraordinary humility and love for the Church, two things that have been the hallmarks of his service," BoehnerJohn Andrew BoehnerFreedom Caucus bruised but unbowed in GOP primary fights GOP revolts multiply against retiring Ryan Can Jim Jordan become top House Republican? MORE said.

"Americans were inspired by his visit to the United States in 2008, and by his quiet, steady leadership of the Church in uncertain times. People of all nations have been blessed by the sacrifices he has made to sow the seeds of hope, justice, and compassion throughout the world in the name of Our Lord and Savior."

Sen. Marco RubioMarco Antonio RubioRepublicans think Trump is losing trade war The Hill's 12:30 Report — Sponsored by Delta Air Lines — Trump meets South Korean leader as questions linger about summit with North Senators demand answers on Trump’s ZTE deal MORE (R-Fla.), considered widely as a possible 2016 presidential contender, praised Benedict's decision.

"Today Pope Benedict XVI displayed the qualities of an excellent leader and a true man of God by putting the interests of the Vatican and the Catholic Church over his own papacy," Rubio said in a statement. "Since becoming Pope in 2005, Pope Benedict XVI has served the Church honorably, particularly through his work promoting charity across the globe. I wish him well in the future and, as a Catholic, I thank him for his service to God and the Church. I also look with optimism toward the future of the Catholic Church as it prepares to welcome a new leader and as it continues to spread God’s message of faith, hope and love to all the corners of the world."

This story was last updated at 12:27 p.m.