Mr Anish Dhakal was just 19 and living in Kathmandu, Nepal, when an earthquake killed 9,000 people and injured thousands more in the country.

Life is fragile, he learnt that fateful day in 2015, when the temblor measuring 7.8 on the Richter scale struck.

"It made me want to do something good with my life. It was not enough to be an environmental activist in Kathmandu any more," Mr Anish, now 21, told The Straits Times.

Together with Mr Dilip Chhetri, 22, and Mr Nirmal Baral, 39, who left their jobs as social workers, Mr Anish is cycling around the world to promote peace and spread awareness of environmental issues.

The trio flew in from Brunei on Monday.

Singapore is their 11th country since their journey began last December.

"I wanted to represent my country, the birthplace of Lord Buddha," Mr Nirmal said on Tuesday, a day ahead of Vesak Day. His wife and two sons, aged 11 and 13, remain in Nepal. Mr Dilip added that his parents are supportive of his endeavour.

The men have travelled about 15,000km, passing through countries such as India, Bangladesh, Myanmar, Thailand and Laos. Their journey, which aims to cover about 100 countries, is funded by the Nepali diaspora.

In every country, they try to educate people, especially students, on the importance of the environment, and how economic success has often come at a price.

In Vientiane, Laos, they took part in a clean-up project as part of a school event.

Asked about their experience in Singapore, Mr Anish said: "A man stopped us as we were cycling from the airport and after hearing about what we are doing, he gave us more than $100."

On Saturday, the trio will start cycling to Kuala Lumpur, before going to the Philippines and Taiwan.