Ukrainian President Volodymyr Zelenskyy has arrived in Japan for talks with G7 leaders.
Mr Zelenskyy and US President Joe Biden are now set to hold face-to-face talks over the weekend at the G7 summit.
President Joe Biden has endorsed the training of Ukrainian pilots to fly F-16s
The timing for when Kyiv will receive the aircraft, how many will be delivered, and which countries will provide them remains unclear, but an official stressed they will not be used for an upcoming counteroffensive against Russia.
Western leaders have argued that training on the aircraft would take too long. It would also be some of the most sophisticated hardware provided for Ukraine, raising the stakes between Russia and the West.