RIYADH • Leaders of the 20 biggest world economies - the Group of 20 (G-20) - will debate this weekend how to deal with the Covid-19 pandemic that has caused a global recession and how to manage the recovery once the coronavirus is under control.

High on the agenda are purchases and global distribution of vaccines, drugs and tests for low-income countries that cannot afford such expenses themselves.

The European Union was to urge the G-20 to invest US$4.5 billion (S$6 billion) to help. It will propose a treaty on pandemics.

In his opening remarks to G-20 leaders, Saudi ruler, King Salman bin Abdulaziz Al Saud, stressed the need for equitable access to the tools to combat Covid-19, including vaccines. "We must work to create the conditions for affordable and equitable access to these tools for all peoples," he told the group via video link.

"An international treaty would help us respond more quickly and in a more coordinated manner," European Council president Charles Michel is expected to tell the G-20 today.

While the global economy is recovering from the depths of the crisis earlier this year, momentum is slowing in countries with resurging infection rates, the recovery is uneven and the pandemic is likely to leave deep scars, the International Monetary Fund said in a report for the G-20 summit.

Especially vulnerable are poor and highly indebted countries in the developing world, which are "on the precipice of financial ruin and escalating poverty, hunger and untold suffering", United Nations Secretary-General Antonio Guterres said on Friday.

To address this, the G-20 will endorse a plan to extend a debt servicing moratorium for developing countries by six months to the middle of next year, with a possibility of a further extension, said a draft G-20 communique seen by Reuters.

European members of the G-20 are likely to push for more.

"More debt relief is needed," Mr Michel told reporters on Friday.

Debt relief for Africa will be an important theme of the Italian presidency of the G-20 next year.

European nations in the G-20 will also seek fresh impetus to the stalled reform of the World Trade Organisation, hoping to capitalise on the upcoming change of the United States administration.

"We must also continue to support the global economy and reopen our economies and borders to facilitate the mobility of trade and people," King Salman said.

Earlier yesterday, Saudi Arabia's Minister of Investment Khalid al-Falih said this year's crisis has highlighted the importance of multilateral organisations.

"The G-20, its essence, is activating multilateralism, and of course this has taken a back seat over the last few years," he said.

Outgoing US President Donald Trump, who attended the summit yesterday, favoured bilateral trade deals over working through international bodies.

The change of US leadership also raises hopes of a more concerted effort at the G-20 level to fight climate change.

Following the example of the EU, already half of the G-20 members, including Japan, China, South Korea and South Africa, plan to become climate-or at least carbon-neutral by 2050 or soon after.

Under Mr Trump, the US pulled out of the Paris Agreement on fighting climate change, but the decision is likely to be reversed by President-elect Joe Biden.

To help finance the fight against climate change, the EU will push for the G-20 to agree on common global standards on what constitutes "green" investment.

This would help attract the massive private investment needed because many investment funds are keen to invest in environmentally sustainable projects, but there is no agreed way of selecting them.

The EU is already working on such standards, and plans to have them in place by 2022.

REUTERS, AGENCE FRANCE-PRESSE