UNITED NATIONS, July 18 (Xinhua) -- Marking Nelson Mandela International Day, UN Secretary-General Antonio Guterres on Tuesday called for actions across the world in promoting peace, sustainable development and lives of dignity for all.

"Nelson Mandela continues to inspire the world through his example of courage and compassion, and his commitment to social justice and a culture of freedom and peace," said Guterres at a ceremony held here in celebration of the Day.

"The best tribute we can pay this great man is not words or in ceremonies, but actions that improve our world," said Guterres.

In November 2009, the UN General Assembly declared July 18, Mandela's birthday, as "Nelson Mandela International Day" in recognition of the former South African president's contribution to the culture of peace and freedom.

Also on Tuesday, president of the UN General Assembly Peter Thomson said today's world is in desperate need of Mandela's values of empathy, kindness, and respect for common humanity as violent conflicts continue to rage and hate crimes against migrants as well as minorities are on the rise.

"His extraordinary strength of character, conviction, and devotion to duty will be an inspiration for all time," he added.