Okonjo-Iweala, a former senior World Bank official was named alongside American lawyer Robert Zoellick to the social media platform's board, the company announced Thursday."We are confident they will be incredible assets to Twitter as we continue to focus on driving transparency and making Twitter a safer, healthier place for everyone who uses our service," Twitter's Executive Chairman Omid Kordestani said.Okonjo-Iweala welcomed the appointment and said she looked forward to leveraging the platform to drive conversations on global issues."As we strive to build a better world for tomorrow, Twitter can amplify messages and drive critical conversations around today's most important issues," she said in a statement.Twitter and other tech giants have faced criticism for a lack of diversity on their board.But some users criticized the company's decision to choose board members that were not active on the platform.Harvard-educated economist Okonjo-Iweala has around 860,000 Twitter followers and hardly engages on the platform, they said. Zoellick, a former World Bank president, joined the social platform February and has not sent out any tweet.But the company's co-founder Jack Dorsey defended the decision saying while many use the platform to drive conversations, the company was open to fresh perspectives from new users."We get critiques about how active board members look on Twitter. Lots of ways to use the service effectively. Some folks use it only to see what's happening!? On us to make it valuable to join the conversation. But we also benefit from folks new to Twitter: fresh perspectives," he said in a tweet.Twitter has over 336 million users and is gaining widespread popularity among Africans who use it to amplify their concerns and create online communities. Like Black Twitter, Kenyans on the platform are vocal and even have their own hashtag:KOT.Twitter recently recognized posting in Swahili, as one of its East Africa's most common languages.