Japan’s prime minister Shinzo Abe and US president Donald Trump may be famed for a friendship nurtured over countless games of golf, hamburgers, late night phone calls and complimentary tweets.

But Mr Abe was united with another high-profile “friend” on Sunday: the former US president Barack Obama, who is joined the Japanese PM for lunch in Tokyo.

Mr Obama arrived on Saturday for a two-day trip in order to attend an international conference, marking his first visit to Japan since he left office in January last year.

Confirming the lunch meeting, Yoshihide Suga, chief cabinet secretary, was quick to emphasise their encounter would not be political but would simply provide an opportunity to deepen their friendship.

His comments conflicted with local media reports earlier this month claiming there would be one key topic which the pair were most likely to discuss while catching up over lunch: North Korea.