Prime Minister Jacinda Ardern will step up for Prince William at the United Nations in the early hours of this morning, New Zealand time, lending her voice to a climate change charity launched by the prince and speaking at an event he was meant to front.
In late August, it was announced that Prince William would travel to New York to give a speech at the Earthshot Price Innovation Summit, which is taking place on the sideline of the United Nations General Assembly.
The death of his grandmother The Queen forced him to cancel.
Ardern, a supporter of the charity, will now take on an expanded role, making opening remarks alongside former New York City Mayor Michael Bloomberg, a billionaire philanthropist.
It is not known whether William asked Ardern to take on the greater role when they met in London last week ahead of the Queen's funeral. Conversations between the prime minister and members of the Royal Family are kept confidential by convention.
The Earthshot Prize seeks out innovative solutions for environmental problems, awarding them funding and connections to turn their ideas into reality and scale them into broader environmental solutions.
About 6am New Zealand time, Ardern is scheduled to appear on a panel with her old boss, former prime Minister Helen Clark, who will be chairing a response on responding to pandemics.
Ardern has time in her schedule for other meetings with world leaders, although these have yet to be announced. Often leaders informally pull one another aside for a brief meeting on the sidelines of other events.
On the first day of the General Assembly meeting, Ardern briefly met with the likes of Samoan Prime Minister Fiamē Naomi Mataʻafa who was attending the event in person for the first time and Iceland's Prime Minister Katrín Jakobsdóttir.
Ardern is one of about 150 world leaders attending the General Assembly's "high level week" in New York. It is the first in-person event since the pandemic.
Secretary-General António Guterres opened the assembly on Wednesday, New Zealand time, with a dark and ominous speech, warning the world was in "big trouble", before questioning whether the United Nations had the ability to rise above geopolitical gridlock and meet those challenges.
The United Nations failed to halt Russia's invasion of Ukraine earlier this year, and Russia's wielding of its veto power on the United Nations Security Council is blocking progress on other areas like nuclear disarmament.
Guterres warned "progress" was " being held hostage by geopolitical tensions".
"Geopolitical divides are undermining the work of the Security Council, undermining international law, undermining trust and people's faith in democratic institutions, undermining all forms of international cooperation," he said.
Ardern said she expected Ukraine would dominate this week at the UN.
"I do believe it will dominate events," Ardern said.
"It should dominate because it does dominate," she said, noting the invasion would have a "cascading" effect on UN members in the form of high energy and fuel prices," she said.
"A winter of global discontent is on the horizon. A cost-of-living crisis is raging. Trust is crumbling. Inequalities are exploding. Our planet is burning," he said.
On Wednesday, New Zealand time, Ardern met with French President Emmanuel Macron, who has become something of a friend on the world stage.
The pair announced research into the way online algorithms can be harmful and help to radicalise people by pushing ever more violent content into their social media feeds.
The initiative was announced as part of the Christchurch call.