The world's poorest countries have said they may struggle to meet visa requirements and cover all COVID-19 quarantine costs for the COP26 climate summit, raising concerns that some might not be able to attend in person.

The UN conference, meant to spur countries to make bigger commitments to slash greenhouse gas emissions, is due to start in Glasgow on Oct. 31.

"We're still concerned about the possibility of getting our delegates to COP26, to negotiate key issues about the global response to climate change that will have such a profound effect on our people," Bhutan's Sonam Phuntsho Wangdi, chair of the Least Developed Countries (LDCs) group, told Reuters.

Britain said last week that government ministers travelling to COP26, plus two staff members, would be exempt from quarantine requirements when they arrive.

But other delegates from countries on Britain's coronavirus "red list", such as Angola, Ethiopia and Haiti, must quarantine in a hotel for up to 10 days before attending the summit.

The government has said it will cover the cost of hotel quarantines for delegates from poorer nations.

Wangdi said some countries' delegations were not led by ministers, meaning they would need to visit a visa centre to complete their application to attend COP26.

Delegates from 25 of the poorer countries would have to leave their territories to go to visa centres in another state - a challenging process during the pandemic.