US President Barack Obama offered "warm wishes" on behalf of the American people to newly elected Pope Francis I on Wednesday, hailing the Argentine as "the first pope from the Americas."
"As a champion of the poor and the most vulnerable among us, he carries forth the message of love and compassion that has inspired the world for more than two thousand years, that in each other we see the face of God," he said.
Argentina's Cardinal Jorge Mario Bergoglio, the archbishop of Buenos Aires, was elevated to the papacy by the College of Cardinals, who met at the Vatican to choose a successor to Pope Benedict XVI who resigned last month.
In Argentina, he is seen as a modest figure, true to his working class roots, and as a moderate theologian. He is also the first ever pope from Latin America and the first non-European to take the post in centuries.
"On behalf of the American people, Michelle and I offer our warm wishes to His Holiness Pope Francis as he ascends to the Chair of Saint Peter and begins his papacy," Obama said in a statement issued by the White House.
"His selection also speaks to the strength and vitality of a region that is increasingly shaping our world, and alongside millions of Hispanic Americans, those of us in the United States share the joy of this historic day," he added.
"Just as I appreciated our work with Pope Benedict XVI, I look forward to working with His Holiness to advance peace, security and dignity for our fellow human beings, regardless of their faith."
Obama's vice president, Joe Biden, is a Catholic and will go to Rome to represent the United States at Francis I's inaugural mass on Tuesday next week.
"I am happy to have the chance to personally relay my well wishes, and those of the American people," Biden said, in a statement from his office.
"The Catholic Church plays an essential role in my life and the lives of more than a billion people in America and around the world, not just in matters of our faith, but in pursuit of peace and human dignity for all faiths."
Around a quarter of Americans are Roman Catholics -- around 80 million people, the fourth largest national group in the global Church.
Obama and his family are Protestant Christians, sharing the faith of about half of US citizens, but he has visited the Vatican, where he met former pope Benedict XVI in July 2009.
His administration and the Church have not always seen eye-to-eye, however, and he has been criticized by bishops opposed to health care laws that would force Catholic organizations to fund employee cover for contraception.