Okonjo-Iweala and South Korean trade minister Yoo Myung-hee are vying to be the first female leader in the WTO's 25-year history, replacing Brazilian Roberto Azevedo, who quit a year earlier than expected at the end of August.
The EU's support for Okonjo-Iweala is considered a strong signal to reinforce the multilateral order and a sign of mutual trust between the bloc and Africa, the official said.
The WTO faces dual challenges: criticism from U.S. President Donald Trump's administration which froze its appeals body by blocking its appointment of judges, and worsening U.S.-China trade relations.
Okonjo-Iweala, 66, a previous Nigerian foreign minister, is an economist and development specialist serving as board chair of global vaccine alliance Gavi. She wants the WTO to help poorer countries access COVID-19 drugs and vaccines.
(Reporting by Gabriela Baczynska; Writing by Foo Yun Chee; Editing by Richard Chang)
