Biden, who will stay in capital city Luanda from Monday to Wednesday, will be the first US president to visit the oil-rich country since it won independence from Portugal in 1975.

With the trip, Biden will finally be fulfilling a promise made in late 2022 to visit sub-Saharan Africa. He will also be seeking to boost the US presence on the continent in the face of rising investment by China.

The lame-duck president, who is set to hand over the White House to Donald Trump on January 20, had originally planned to go in October, but had to reschedule due to Hurricane Milton making landfall in Florida.

"This is not too little, too late," a senior US official said in an interview with reporters. "I think that after years of being off the field, President Biden has put us back on."

In Luanda, Biden will discuss various US investments in the region, starting with the "Lobito Corridor," a major rail project linking Angola's port of Lobito to the Democratic Republic of Congo (DRC), with a branch line extending to Zambia.

The 800-mile project (1,300 kilometers) -- funded by the United States and the European Union and described by Biden as "the biggest US rail investment in Africa ever," -- strategically links the port with cobalt and copper mines, key raw materials for smartphone batteries and other tech manufacturing.

Biden is also set to meet Angolan President Joao Lourenco and give a speech on public health, agriculture, military cooperation and cultural heritage preservation.

"Despite President Biden being on his way out of the White House, he will be representing the USA with all its geopolitical and geo-economic weight," said Heitor Carvalho, an economist at Lusiada University in Luanda.

- Debt and China -

Human rights organizations have urged Biden to raise Angola's human rights record on his trip.

According to a recent report by human rights NGO Amnesty International, Angolan police have killed at least 17 protesters, including one minor, as part of a long-running crackdown on dissent.

The nonprofit also urged Biden to demand that Angola "immediately release five government critics arbitrarily detained for more than a year."

"President Biden has never shied away from talking about challenges to democracy, his commitment to democracy," the senior US official said.

Biden is also concerned, however, with reasserting US ambitions in Africa in the face of encroaching influence by China.

The senior official told journalists that African governments are seeking an alternative to Chinese investment, especially when it results in "living under crushing debt for generations to come."

Angola, for instance, owes China $17 billion, about 40 percent of the nation's total debt.

Lourenco, too, appears to want to diversify his country's partnerships beyond China and Russia.

In 2022, for instance, Angola voted in favor of a United Nations resolution condemning the invasion of Ukraine.

For the Angolan president, Biden's visit "must be the fulfillment of his dream of being 'the one' who brought the first American president to Angola," said Cesaltina Abreu, a sociologist at the Catholic University of Angola.

Despite Biden's efforts, it remains unknown whether US investments in Africa will continue during the Trump administration.

"If Trump makes as much of Africa and Angola as he did in his first term, there will be a setback in programs started by Biden," Abreu added.

But the Republican president-elect should keep in mind that "Angola, and countries like it, have many partners to choose from in a world of increasing competition for access to Africa's vital resources," warned Alex Vines, a researcher at international think tank Chatham House.