South Africa and Nigeria have been drawn into a sweeping United States trade investigation as Washington intensifies its efforts to confront what it deems unfair global trade practices.

The US has launched a Section 301 investigation into the trade practices of 60 economies, including South Africa and Nigeria, citing concerns about unfair competition and forced labour. 

The probe aims to determine whether these countries are allowing goods produced by forced labour into their markets or benefiting from other unfair trade practices.

Trade relations between the US and South Africa have become increasingly strained, especially after Washington imposed tough tariffs and boycotted major diplomatic events. The move follows a Supreme Court decision limiting tariff use, which has pushed the US to rely more heavily on legal mechanisms like Section 301 to address perceived global trade injustices.

The Office of the United States Trade Representative (USTR) has launched a Section 301 investigation into South Africa and Nigeria, as well as the European Union, to determine whether they are engaging in “unfair trade.”

The investigation forms part of a broader push by the US government to “level the playing field” between domestic production and foreign imports that are often cheaper. Trade Representative Jamieson Greer said the probe will focus primarily on forced labour but could extend to other practices considered unfair to US commerce.

Notably, the investigation is not only examining whether countries produce goods using forced labour, but also whether they allow such goods to enter their domestic markets. The investigations are an initial step to determine whether listed governments—particularly South Africa and Nigeria, two of Africa’s largest economies—have taken sufficient measures to prevent the importation of goods produced through forced labour.

“For too long, American workers and firms have been forced to compete against foreign producers who may have an artificial cost advantage gained from the scourge of forced labour,” Greer said.

Speaking to CNBC, Greer clarified that the investigation could go beyond labour issues. “If we find that countries have been engaging in unfair trading practices, like subsidies, excess capacity, or allowing goods made with forced labour into their countries, we can quantify that harm to US commerce and then try to resolve that issue with that country,” he said.

The investigation follows a recent United States Supreme Court ruling that struck down key tariffs introduced during President Donald Trump’s earlier trade policy push. The decision removed several tariffs on foreign imports, prompting Washington to rely more heavily on legal mechanisms such as Section 301 investigations to address disputes with trading partners.

The latest probe adds another layer of pressure to US trade relations with several African economies, particularly two of the continent's largest: South Africa and Nigeria, both of which were affected by the administration’s tariff measures.

Relations between Washington and Pretoria have been strained since President Donald Trump returned to the White House in January 2025. South Africa faced some of the toughest tariffs during the administration’s “reciprocal tariff” measures, with duties of up to about 30% imposed on some exports. 

The United States also boycotted the G20 summit hosted by South Africa in November 2025.

South Africa’s participation in the African Growth and Opportunity Act (AGOA) programme has also faced scrutiny. Although the trade programme was renewed in February and remains in force until December 31, 2026, the list of eligible countries can still be revised. South Africa’s Department of Trade, Industry and Competition has been attempting to negotiate a more favourable trade arrangement with Washington since April 2025, but talks have made little progress.

Nigeria was also affected by the tariff measures, facing duties ranging roughly between 10% and 20% on selected exports, particularly in sectors where Washington argued Nigerian trade policies limited access for American goods. The measures mainly affected agricultural exports and some manufactured products, according to reports on the tariff policy. However, Nigeria was less politically targeted than South Africa, with US concerns largely centred on import restrictions and currency policies rather than broader diplomatic disputes.