LONDON: Many of Kaka's 23.4 million Twitter followers, may have found a post on the Brazilian soccer star's feed last week a bit confusing.

In contrast to tweets praising Jesus or the celebrity selfies that usually dominate his timeline, the post read: "Most of my life I've been helping climbers from all over the world hike the mountains of Nepal. #ShareHumanity".

My feed won’t be the same over the next day. It’s for a very special cause: #ShareHumanity

— Kaka (@KAKA) August 12, 2015

— Kaka (@KAKA) August 12, 2015

Most of my life I’ve been helping climbers from all over the world hike the mountains of Nepal. #ShareHumanity pic.twitter.com/QvCRrxxxCu

— Kaka (@KAKA) August 12, 2015

Meet Don Bowie from Canada. I am a guide on his team. Tomorrow we will make the push for the summit. #ShareHumanity pic.twitter.com/fmHuyvyvz5

— Kaka (@KAKA) August 12, 2015

My family’s home has been destroyed, I want to be with them, but I’m needed here. I’m joining @WFP. #ShareHumanity pic.twitter.com/XSmx4HdivQ

— Kaka (@KAKA) August 12, 2015

In the middle of the night the ground started shaking. We’re all safe but hundreds of villages are flattened. #ShareHumanity

— Kaka (@KAKA) August 12, 2015

My name is Nuri Sherpa. Thank you for giving me the opportunity to tell my story. pic.twitter.com/9KNbvqzVwD

— Kaka (@KAKA) August 12, 2015

As part of a social media campaign to mark World Humanitarian Day on Wednesday, Kaka "donated" his Twitter feed to Nuri Sherpa, who trekked through snow to bring food to remote areas in Nepal hit by a devastating earthquake in April.

The global campaign, using hashtag #ShareHumanity, aims to shine a light on people struggling in conflict zones or areas hit by natural disasters.

Besides Kaka, who now plays for Orlando City in the United States after a decade with AC Milan and Real Madrid, the campaign has also enlisted the likes of Australian teenage pop star Cody Simpson and Chinese pianist Lang Lang.

"We're calling on the young and digitally-connected to help us push out these compelling stories and give a voice to the voiceless," said Stephen O'Brien, U.N. humanitarian chief, in a statement.

World Humanitarian Day was established seven years ago to commemorate the 22 people killed when the United Nations' headquarters in Baghdad was bombed on August 19, 2003.

Cody Simpson, with 7.5 million followers, gave his feed to Thair, a Syrian refugee with just a few hundred followers who travelled from Damascus to Berlin, posting a picture of migrants crowded onto a boat in the Mediterranean along the way.

"It's been going really well," said Natasha Scripture, a U.N. spokeswoman. "We want to create a mass core of support for humanitarian life-saving action in the world today."

"We've got to the point where humanitarian needs are outstripping our ability to respond," she said, adding that the United Nations would be appealling for close to $20 billion later this year to help respond to the world's emergencies.