Kuwait is planning to "double or triple" its investment in Japan, in a move that could take its total commitment to $50bn, according to Mustapha al-Shamali, the Gulf state's finance minister.

Both Mr Shamali and Bader al-Saad, head of the Kuwait Investment Authority, have been on a visit to Asia with Sheikh Nasser al-Mohammad al-Sabah, the Kuwaiti prime minister.

The finance minister was quoted announcing the increased investment on Sunday by the Kuwait state news agency.

The KIA has steadily increased its investment in Asia in recent years. So far, China has been the main beneficiary of the KIA's interest. The sovereign wealth fund has a major stake in Industrial & Commercial Bank of China and has been looking to invest in property in China's second-tier cities such as Dalian. In addition, it has been looking to take stakes in south-east Asian banks, particularly in Vietnam.

Kuwait and Japan have also reached an agreement in principle to end or reduce double taxation on interest, dividends, capital gains and other investment income. Japan has similar agreements with about 60 countries, but a deal with Kuwait would be its first with an oil-rich Middle Eastern state.

According to the Japanese foreign ministry, Yasuo Fukuda, Japan's prime minister, and Sheikh Nasser agreed to conclude a deal "at the earliest possible time", during a visit by the Kuwaiti prime minister to Tokyo late last month.

Continued at FT.com