Japan, lagging behind China in securing minerals and energy from Africa, will help develop resources in Botswana, according to Ryoichi Matsuyama, the new Japanese ambassador to the world's largest diamond producer.

"Botswana is Japan's last chance in Africa to engage in resource diplomacy, where China has a lead," Matsuyama, who will become Japan's first envoy to the nation at the end of May, said in an interview in Tokyo last week.

China has diplomats in 48 African nations, double that of Japan, as the world's most populous nation works to tap into the region's resources. The appointment of Matsuyama, 59, who formerly worked at trading house Mitsui & Co., follows trade minister Akira Amari's visit to Botswana last year to help companies secure minerals access.

"China has 750,000 of its nationals residing in Africa, whereas Japan has just 6,000," Matsuyama said.

Matsuyama said he will follow through on a deal last year between Japan Oil, Gas and Metals National Corp. and Botswana's Ministry of Minerals, Energy and Water Resources to explore minerals with Japanese satellite technology.

"Japan is ahead of China in satellite exploration. We don't know what's buried there, but we would like to develop ventures with Botswana, like the one it has for diamonds," Matsuyama said.

Botswana faces the challenge of diversifying its economy to reduce its dependence on diamonds, which account for 75 percent of exports and almost two-thirds of government revenue. The gems are produced by De Beers, the world's biggest diamond company, through a joint venture with the state.

Botswana, slightly smaller than Texas and with a population of 1.8 million, borders South Africa, Namibia and Zimbabwe. Its Aa3 credit rating by Moody's Investors Service is the highest in Africa.