In a statement to mark the U.N. International Day of Remembrance of the Victims of Slavery, the veteran Portuguese Socialist said past colonial powers "laid the foundations for a violent discrimination system based on white supremacy that still echoes today.

"Descendants of enslaved Africans and people of African descent are still fighting for equal rights and freedoms around the world. Today and every day, we reject the legacy of this horrific crime against humanity.

"[…] We call for reparatory justice frameworks to help overcome generations of exclusion and discrimination."

In September, a U.N. report suggested countries should consider financial reparations to compensate for slavery.

"This is the movement that will signal, finally, the collective victory of humanity, of good over evil," Hilary Beckles, chair of the reparations commission of the Caribbean Community political and economic union, or Caricom, said at the U.N. General Assembly.

The Caricom reparations commission was set up to seek reparations, including debt cancellations and support to tackle public health crises, from former colonial powers such as the United Kingdom, France and Portugal.

The demand for financial reparations has also been heard in the United States.