Hillary Clinton is showing her respect for departing New Zealand Prime Minister Jacinda Ardern.

The former U.S. secretary of state, 75, called Ardern, 42, “a true stateswoman” as she shared a tribute to the youngest female head of government in the world, who made the sudden announcement of her resignation on Thursday.

“Jacinda Ardern will be remembered for guiding her country with strength, compassion, and grace through multiple historic crises, doubtless saving countless lives,” Clinton wrote Thursday on Twitter. “She’s shown the world a new model of powerful leadership. A true stateswoman.”

Ardern revealed on Wednesday that she does not plan to seek re-election after beginning her historic first term as the country’s 40th prime minister in 2017 at age 37. She plans to exit the position early, by Feb. 4, putting the Labour Party into a scramble to find a new party leader with two-thirds support.

“I know what this job takes. And I know that I no longer have enough in the tank to do it justice. It’s that simple,” she announced, explaining that she does not have the energy to lead the country through the Oct. 14 general election.

“I had hoped that I would find what I needed to carry on over that period,” Ardern added. “But, unfortunately, I haven’t, and I would be doing a disservice to New Zealand to continue.”

The politician said that she hopes to spend more time with TV host partner Clarke Gayford and their 4½-year-old daughter Neve Te Aroha following her resignation.

Although New Zealand polling showed the Labour Party trailing slightly behind the National Party in October, according to NPR, Ardern has the utmost confidence in her party.

“I’m not leaving because I believe we can’t win the election, but because I believe we can and will, and we need a fresh set of shoulders for that challenge,” added Ardern.