The search for the billions of dollars still needed to fight climate change topped the agenda Thursday as world economic leaders met seeking to kick-start growth while tackling global warming.

With two months to go to a key UN conference in Paris tasked with delivering a comprehensive climate deal, finance ministers and central bank chiefs from 188 countries have put funding to fight global warming atop the agenda along with traditional economic issues as they meet in the Peruvian capital Lima this week.

Wealthy nations have pledged to come up with $100 billion a year by 2020 to help poorer nations fight the impacts of climate change, but a report released on the eve of the annual meetings of the International Monetary Fund and World Bank found the world was still $38 billion short of that target last year.

The issue has been a major sticking point in previous UN climate talks.

"If we want the Paris conference to be a success, the question of funding has to be nine-tenths settled, if not 100 percent," French Finance Minister Michel Sapin told journalists.

He called on development banks like the World Bank to give more climate financing, warning that governments have given nearly all they can to get to the $62 billion in funding that the Organisation for Economic Cooperation and Development (OECD) says the world came up with in 2014.

The World Bank and other multilateral institutions "haven't done a lot," said Sapin.

"The dynamic now belongs to the multilateral system and the private sector."

World Bank chief Jim Yong Kim said his institution "stands ready to scale up its support" to countries in the climate change fight, but did not give a figure.

"We'll be having active discussions with our shareholders in the coming days to do all we can to help the world find solutions," he told a press conference.

- China's slowdown hits recovery -

Coming up with new cash is tricky with the world economy set to register its weakest growth this year since the global recession of 2009, according to a new IMF forecast released ahead of the meetings.

The slowdown in China, which is on track for its lowest growth in 25 years next year, is having an impact worldwide.

After decades of break-neck expansion, the world's second-largest economy is losing its voracious appetite for fuel, metals, minerals and other commodities, sending prices slumping and hurting the fellow emerging markets that export them.

The economic pain is particularly acute in Latin America, which had not hosted the IMF annual meeting since the 1967 edition in Rio de Janeiro, Brazil.

But IMF chief Christine Lagarde insisted the world economy was in recovery despite the turbulence.

"We should just first of all remind ourselves that growth is (forecast) at 3.1 percent (for 2015), so there is recovery," she told journalists.

"We all need to get used to these little bumps on the road" as China transitions to a market-based economic model driven by domestic consumption, she said.

The fifth annual slowdown for the once-mighty emerging markets and the commodities plunge underpinning it will also be key agenda points as finance ministers from the leading industrialized and emerging economies gather for a G20 meeting, before issuing a statement Friday.

They will also discuss the OECD's new plan to crack down on tax avoidance worldwide, after it declared Monday that "playtime is over" for multinational corporations that stiff countries on more than $100 billion a year.

The G20 finance ministers must give the plan the green light in Lima and pass it on to their bosses for final approval, expected in November at a G20 summit in Turkey.

An entire neighborhood of Lima has been closed off with military checkpoints for the occasion, leaving the streets bizarrely empty in the normally traffic-jammed city and creating headaches for commuters.

Protesters have vowed to try to march on the meeting venue Friday.