GABORONE (Reuters) - Chinese Vice President Xi Jinping on Sunday signed several economic deals with Botswana, the worlds biggest diamond producer, including one offering the southern African country $6 million for development. Xi, touted as Chinas next president, arrived in Botswana on Saturday, the last stop on his Africa tour, after visiting oil producer Angola, Chinas biggest African trading partner, and South Africa Africas biggest economy. Vice President Mompati Merafhe and Xi signed three cooperation deals, including an Economic and Technical Cooperation agreement, under which China is to provide Botswana with aid worth 40 million RMB ($6m), Chinas Xinhua news agency reported. The two also signed an infrastructure and energy deal between the national utility Botswana Power Corporation and China Development Bank and Golden Concord Group, it said. The other agreement was on financial projects between the Botswana government and the Export-Import Bank of China. No monetary details were provided on the other two deals. Xi on Wednesday signed an energy deal with South Africa in a visit aimed at obtaining minerals the Asian giant needs to fuel its blistering growth. During his two-day visit, Xi is expected on Monday to tour Diamond Trading Company Botswana, which is jointly owned by the diamond-mining giant De Beers and the government of Botswana. Chinas mineral diplomacy has been criticised for its secrecy and for bolstering governments that Western states accuse of human rights violations. A senior World Bank executive said Chinese companies eyeing African mineral resources must stop making closed-door deals and become more transparent in their investments. (Writing by Olivia Kumwenda