It doesn't take long after first meeting New Zealand's Prime Minister Jacinda Ardern to discover that she seems to be all that she is reputed to be: vivacious, relatable, disarming, informal, masterful at putting people at their ease, a politician who wears her authority lightly.

As we settle down to the interview in a meeting room at the Parkroyal Collection Pickering hotel this week during her visit to Singapore, she invites me to pour myself some water so I can take off my mask. She takes hers off too, reaching for a cup of tea. To break the ice, she begins with small talk.