Bhutan has very warm relations with Japan, which provides significant development assistance. The Bhutanese royals were hosted by the Japanese imperial family during a state visit in 2011. Japan is also helping Bhutan cope with glacial floods through developing an early warning system. Bhutan enjoys strong political and diplomatic relations with Bangladesh. The Bhutanese king was the guest of honor during celebrations of the 40th anniversary of Bangladesh's independence. A 2014 joint statement by the prime ministers of both countries announced cooperation in areas of hydropower, river management and climate change mitigation. Bangladesh and Bhutan signed a preferential trade agreement in 2020 with provisions for free trade.