Pretoria - US President Barack Obama has praised Archbishop Desmond Tutu on his official retirement, calling him a moral titan and dedicated peacemaker.
The Nobel laureate formally stepped away from public life on Thursday to spend more time at home with his family.
Obama said Tutu was the voice of the voice of the voiceless. "For decades he has been ... a voice of principle, an unrelenting champion of justice."
He lauded Tutu for playing a pivotal role in overturning apartheid and his extraordinary efforts to pursue reconciliation in the new South Africa.
"He has also been an outspoken voice for freedom and justice in countries across the globe; a staunch defender of the rights of lesbian, gay, bisexual and transgender persons and an advocate for treatment and prevention programs to stop the spread of HIV/AIDS," Obama said.
Tutu announced in July he would retire on his 79th birthday, which fell on Thursday, after years fighting for justice and an end to apartheid in South Africa and crossing the globe to highlight global human rights struggles.
His work, including leading the Truth and Reconciliation Commission which uncovered the horrors of apartheid-era abuses, earned him a Nobel Peace Prize in 1984 for his non-violent struggle against apartheid.
The US president said Tutu will be missed for his insight and activism, but will continue to learn from his example.
"We wish the archbishop and his family happiness in the years ahead."
