In pictures: South Korea's heatwave-hit scout jamboree bracing for Typhoon Khanun

Organisers of the World Scout Jamboree in South Korea, who have been grappling with a debilitating heatwave for days, were on Monday preparing for a typhoon to batter their huge campsite with wind and rain, officials said.

The World Organization of the Scout Movement said it received confirmation from South Korea’s government of the early departure for all participants in the southwestern county of Buan. That means quickly moving about 40,000 scouts from 158 countries, mostly teenagers, out of the storm's path.

The government and organisers have pledged that safety is top priority, and have laid on water trucks, air-conditioned spaces and medics. But a new danger is looming with Typhoon Kanun due to reach southern South Korea early on Thursday, with strong winds and rain expected, forecasters said.

South Korean President Yoon Suk Yeol’s office said he called for “contingency” plans to protect the scouts from the storm, which could include relocating them to hotels and other facilities in the country’s capital, Seoul, and nearby metropolitan areas.

"To ensure the safety of the World Jamboree, we are discussing detailed countermeasures for the typhoon situation with relevant agencies including the interior ministry," gender equality minister Kim Hyun-sook told a briefing.

The World Organization of the Scout Movement said in a statement it was monitoring the weather and would ask for help if heavy rain was likely to hit the campsite in an area of reclaimed land in Buan county in southwestern South Korea.

The Australian contingent became the latest troop to leave the campsite, citing the typhoon risk, Australian broadcaster ABC reported. The US and British contingents have already left because of the heat, with the Americans due to stay at a US army base and the British at hotels in the capital, Seoul.

Singaporean scouts have also moved into accommodation elsewhere but were taking part in on-site activities, the organisers said.

A K-pop concert due to be held at the campsite on Sunday was postponed to Friday and will be held at sports stadium, some 53 km (33 miles) away. Organisers have come in for criticism from parents and the public for failing to anticipate the heat.

Kim Kwan-young, governor of North Jeolla province hosting the event, apologised on Sunday for not being prepared. Various authorities and businesses have stepped in to help, donating water and ice cream, while the Jogye Order of Korean Buddhism has opened up its temples to the scouts.