Swedish climate activist Greta Thunberg has sailed into New York for a UN summit, marking the end of a 15-day journey across the Atlantic in a zero-carbon yacht.
The 16-year-old was photographed waving at journalists and well-wishers as she neared the end of her 5,550km trip.
Speaking to reporters shortly after arriving, Greta said the ground was still shaking but the journey had been "surprisingly good".
"I did not feel seasick once," she said, to laughs and cheers.
Despite arriving in the US for the first time, which is under the leadership of climate sceptic Donald Trump, Greta dismissed questions on whether she would be trying to convince the President to address the issue of climate change.
"Everyone always asks me about Trump - my message for him is listen to the science, and he obviously doesn't do that," she said, adding that she would instead focus her energy on spreading awareness.
"This is a fight across borders, across continents. It's insane that a 16-year-old would have to cross the Atlantic ocean to make a stand," she said.
"If we do not manage to work together and cooperate ... then we will fail. We need to stand together and support each other.
"Let's not wait any longer, let's do it now."
Her yacht had earlier anchored off the entertainment district of Coney Island in Brooklyn to clear customs and immigration.
The UN sent a flotilla of 17 sailboats, one for each of their sustainable development goals for 2030, to meet her for the last short leg of her journey.
She set sail to attend a UN summit on zero-emissions next month after refusing to fly there because of the carbon emissions caused by planes.
Greta was offered a ride on the Malizia II racing yacht skippered by Pierre Casiraghi, the son of Monaco's Princess Caroline, and German round-the-world sailor Boris Herrmann.
The yacht left Plymouth in southern England on 14 August, and the teenager marked the first anniversary of the start of her school strike on 20 August.
Greta began sitting outside the Swedish parliament in August 2018 to get members of parliament to act on climate change.
She was quickly joined by other students around the world, as word of her strike spread through the media, and the "Fridays for future" movement was born.
The 18m yacht features state-of-the-art solar panels on its deck and sides, and two hydro-generators provide the vessel's electricity.
It can travel at speeds of around 70km/hour.
The Swede has endured cramped and rudimentary conditions onboard, eating freeze-dried food and using a bucket as a toilet.
Greta said earlier in the week that she expected to arrive in New York on Tuesday but rough seas south of Nova Scotia slowed their progress.
The teenager has become a figurehead for climate action with her stark warnings of catastrophe if the world does not act now to cut carbon emissions and curb global warming.
Her voyage sparked controversy after a spokesman for Mr Herrmann told Berlin newspaper TAZ that several people would fly into New York to help take the yacht back to Europe.
Mr Hermann himself will also return by plane, according to the spokesman.
Team Malizia's manager insisted, however, that the young activist's journey would be climate neutral, as the flights would "be offset".
Greta has said that she does not yet know how she will return to Europe.
Ahead of the UN summit on 23 September, Greta will take part in youth demonstrations, before heading to Canada, Mexico and then to Chile for another UN conference in December.
