President Joe Biden on Tuesday, during his diplomatic trip to Angola, acknowledged America’s “original sin” of slavery and the slave trade that once connected the United States and the African nation.

“I’ve learned that while history can be hidden, it cannot and should not be erased,” Biden said. “It should be faced. It’s our duty to face our history. The good, the bad and the ugly. The whole truth. That’s what great nations do.”

The remarks were delivered at the National Museum of Slavery, where millions of African slaves were baptized before being chained in ships to travel across the Atlantic Ocean.

“We’re gathering in a solemn location because to fully consider how far our two countries have come in our friendship, we have to remember how we began,” Biden said outside the museum on a rainy afternoon.

“We hear them in the wind and the waves: young women, young men born free in the highlands in Angola, only to be captured, bound and forced in a death march along this very coast to this spot by slave traders in the year 1619,” Biden said.

The White House announced earlier this week, as Biden arrived in Angola, that it was giving a $229,000 grant to help with a restoration of the museum and its conservation.

The diplomatic trip is aimed at deepening the relationship between the two countries, and marks the first-ever visit to Angola by a sitting U.S. president and the first sub-Saharan trip by an American leader since President Barack Obama in 2015.

Biden kicked off the visit with a bilateral meeting earlier Tuesday with President João Lourenco in Luanda.

The two men talked about trade and economic opportunities, protecting democracy and the growth of the U.S.-Angola relationship, according to the White House.

Biden celebrated the partnership further in his remarks, saying it’s as “strong as it’s ever been” and that the “United States is all in on Africa’s future.”

“The story of Angola and the United States holds a lesson for the world: two nations with a shared history in evil of human bondage, two nations on opposite sides of the Cold War defining struggle in the late part of the 20th century,” Biden said. “And now two nations standing shoulder to shoulder, working together every day for the mutual benefit of our people.”

“It’s a reminder that no nation need be permanently the adversary of another testament to the human capacity for reconciliation and proof that from every — from the horrors of slavery and war, there is a way forward,” Biden added.

On Wednesday, Biden will tour part of the Lobito rail corridor, which is being partially financed by the U.S., that will help transport goods and materials across Africa — a development seen as a way to counter China’s influence in the region.

White House National Security Communications Adviser John Kirby touted the project in an interview with ABC News’ Alex Presha.

Kirby said the administration was “very confident that the Lobito corridor is going to be a success,” noting it’s a multilateral effort with support from U.S. allies and benefits American companies that will build part of the railway at home before it’s transported to Africa.

Looming over Biden’s historic visit, though, was the decision to pardon his son Hunter Biden. Biden has not answered reporters’ shouted questions on the pardon while he’s been in Angola.

Asked if the pardon has diverted attention away from Biden’s trip, Kirby said Biden is focused “on important this is, again, not just to the people of Angola and the continent, but to the American people.”

ABC News’ John Parkinson contributed to this report.