Around 40,000 people gathered for the concert headlined by NewJeans and IVE at Seoul's World Cup stadium.

"I'm sorry that the scout members suffered from unprecedented heat waves and typhoons caused by climate change," Prime Minister Han Duck-soo said at the closing ceremony.

Han had earlier said the government would "use its all resources to ensure that the jamboree can end safely".

Organisers have been desperate to avoid any further problems at the jamboree, the first global gathering of scouts since the COVID-19 pandemic.

Since the event began last week, hundreds of participants had fallen ill after temperatures hit 35 degrees Celsius (95F) in Saemangeum, the area of reclaimed land on South Korea's west coast where the scouts aged 14-18 were camping.

Britain's contingent decided to leave the campsite early with its head also blaming their departure on poor sanitation and lack of food.

U.S. and Singapore scouts followed suit, throwing a global spotlight on the poor preparations for the event.

The remaining scouts were then evacuated due to safety concerns ahead of an approaching typhoon, and taken by more than 1,000 buses to accommodation around Seoul.

Amid embarrassment over the fate of the scouts, some ordinary South Koreans took matters into their own hands - in one case offering them gifts at a Seoul subway station, while a cafe in North Jeolla Province sent food.

Politicians from across the political spectrum have called for a closer look at why the event was so poorly managed. A spokesperson for the main opposition Democratic Party of Korea last week labelled it "a national disgrace on an epic scale".

K-pop agency HYBE and tech group Kakao said they were providing free merchandise for scouts attending Friday's concert.

Around 1,000 staff from state organisations were also asked to volunteer at the K-pop concert, a government official said.

Citing the floods, heat wave and typhoon, a top scout official described the jamboree, which began on Aug. 1, as one of the most challenging to date.

"It is the first time in over 100 years history of World Scout Jamborees to face such compounded challenges," Ahmad Alhendawi, Secretary General of the World Organization of the Scout Movement, said in a statement on Tuesday.

($1 = 1,325.0700 won)

(Reporting by Hyunsu Yim; Editing by Ed Davies and John Stonestreet)

By Hyunsu Yim