China's zero-tariff access for Africa's least developed countries kicked in this week, a senior Chinese diplomat said, just as U.S. President Joe Biden visits Angola.

Speaking of “our nation’s original sin,” President Joe Biden on Tuesday toured a slavery museum in Angola and inspected shackles and a whip but also addressed Africa’s future.

Biden's visit to oil-rich Angola seeks to underline an attempt by America to focus more on trade and heavy investment in infrastructure, in what some analysts see as the most direct counter yet to China’s influence on the continent. "It’s a perfect marriage of convenience," Angolan analyst Edmilson Angelo told the BBC.