Washington: Swedish teenager Greta Thunberg, who shot to global fame for inspiring worldwide student strikes to promote action against climate change, took her mission to US President Donald Trump’s doorstep on Friday with a protest outside the White House.

Thunberg, wearing a blue hooded sweatshirt with her hair loosely pulled back in a ponytail, was greeted with a hero's welcome by hundreds of mostly young people carrying signs reading "If you did your job, we would be in school" and chanting "This is a crisis, act like it!" and "Business as usual is not enough."

"This is very overwhelming," she said softly into a megaphone after a march in front of the White House in which she walked amidst the other activists instead of in front. Sometimes it was hard to hear her over the cheers.

"See you next week," she said toward the end of the event, referring to a planned September 20 global "Climate Strike" in which youth and adults are encouraged to walk out of school or work to urge more action on climate change.