WASHINGTON — President Barack Obama and first lady Michelle Obama say the world can honor Nelson Mandela by heeding his example and serving others.

The Obamas are sending their wishes and prayers to the former South African leader on his 95th birthday. Mandela is critically ill in the hospital, although he's said to be improving and could be discharged soon.

The Obamas met with Mandela's family last month while in South Africa and visited Robben Island, where the anti-apartheid figure spent 18 years as a political prisoner

The president and first lady say they were deeply moved by the visit to the prison. They say they will forever draw strength and inspiration from Mandela's example, They say his commitment to equality, dignity and reconciliation should be a beacon for future generations.