CAPE COAST, Ghana (REUTERS) - US First Lady Melania Trump laid a wreath at a 17th-century slave fortress in Ghana on Wednesday (Oct 3), vowing never to forget where Africans were held before being shipped away into further hardship, most across the Atlantic.

Ghana is the jumping-off point for her first major solo international trip for Melania as first lady, a tour of Africa, a continent her husband reportedly referred to derisively. She will visit Malawi, Kenya and Egypt as well.

"It's very emotional... I will never forget (the) incredible experience and the stories that I heard," she said after seeing the dungeons and walking through the so-called "door of no return," the castle's final exit towards the Atlantic Ocean.

President Donald Trump has not visited Africa since taking office in 2017. In January, US media reported widely that he had described African states as "s***hole countries" during a discussion with lawmakers about immigration. He has denied making the remark.

The Cape Coast castle, now a monument, has attracted world dignitaries including Trump's predecessor, America's first black president Barack Obama, his wife, Michelle, and their two children.

Obama likened the tour to his visit to the site of the former Nazi concentration camp at Buchenwald in Germany, saying it was reminiscent of the capacity of human beings to commit "great evil." A plaque at the Ghana fortress commemorates Obama's visit.

During her tour on Wednesday, Melania Trump walked slowly with a guide through various wings, asking questions. She passed a row of cannons and descended into a dungeon where male slaves were held in chains.

"It's really, really touching," she said. "The dungeons that I saw, it's really something that people should see and experience, and what happened so many years ago - it's really a tragedy."

After passing through the "door of no return", she placed a wreath nearby and stood solemnly while her guide sang.

Before proceeding to the slave castle, she visited the palace of the head chief of the area and obtained royal approval to visit the fortress after US officials presented a gift of drinks to the chiefs.

The ceremony took place in Obama Hall at the Emintsimadze Palace, which was renamed in Obama's honour after his visit in 2009.

Melania Trump has made advocating for children her signature issue since becoming first lady. A US official said the chief had invited two disabled children from a nearby school to the ceremony with the first lady, a break from local tradition in which it had previously been considered taboo to have anyone with handicaps in the palace.