Chinese social media users have been discussing how Mr Walz spent a year teaching in the south-eastern province of Guangdong in 1989 - a topic that was trending on Weibo with 12 million views.

He and his wife, fellow teacher Gwen Whipple, later honeymooned in the country.

Mr Walz once described his decision to teach in China as “one of the best things I’ve ever done”.