Paddles, the New Zealand prime minister's ginger cat, had six toes and a wide social media following but has run out of lives.

Jacinda Ardern, the charismatic new leader, announced the death of the "prime moggy" on Wednesday after Paddles was hit by a car the previous evening, prompting an outpouring of grief on social media.

Paddles' rise to social media fame matched her 37-year-old owner's meteoric ascent to the prime ministership after only taking over as leader of her Labour Party in August.

A "First Cat of NZ" Twitter account was set up by an anonymous user last month, with regular tweets about the photogenic cat's famous "mummy," Ardern. It quickly attracted 11,000 followers.

People from around the world posted messages such as "rest in peace" and "gone too soon" with the hashtag #paddles.

The polydactyl cat's feats included being able to hold a pair of glasses with her opposable thumb. She featured regularly in photos of Ardern at work.

"To anyone who has ever lost a pet, you'll know how sad we feel. Paddles was much loved, and not just by us. Thanks for everyone's thoughts," Ardern wrote on Facebook.

Ardern's rise to power has generated intense interest in her personal life and drew comparisons with other youthful trailblazers such as France's Emmanuel Macron and Canada's Justin Trudeau.

According to Ardern's partner, Clarke Gayford, Paddles often played her part in affairs of state, even interrupting the premier's first call with U.S. President Donald Trump in October.

"As the call was transferred our cat (yes that bloody cat) came flying through the cat-flap," Gayford, a television presenter, wrote in a column for the Spinoff news website. "She leapt up onto the chair next to Jacinda and began announcing her very squawky arrival," he wrote.