A solar-powered plane attempting to make an unprecedented flight across the Pacific is being forced to make an unscheduled stop in Japan due to poor weather conditions.

Solar Impulse 2 is en route from China to Hawaii but will make a detour to Nagoya. It took off early on Sunday for a six-day, six-night, flight over the Pacific Ocean.

Pilot André Borschberg, 62, left Nanjing, in eastern China, at about 2.40am following extended delays due to weather-related safety concerns. The 5,270-mile (8,500km) flight would have been a record for duration by a single pilot.

Borschberg was asked to circle over the Sea of Japan while meteorologists assessed the situation. They have now decided not to proceed, and the plane is scheduled to arrive at the Komaki airfield at 1pm GMT.