Finance ministers and central bankers from the Group of 20 leading and developing economic powers kicked off a summit here Saturday, amid differing views on the eurozone debt crisis.
The meeting started at the Chapultepec Castle in Mexico City shortly before 7:00 pm (0100 GMT), a source from the presidency of Mexico, which currently heads the G20, told AFP.
Top officials, including US Treasury Secretary Timothy Geithner, called on the eurozone to boost its firewall to prevent the crisis spreading throughout the bloc but Germany, Europe's paymaster, immediately slapped down the idea.
The ministers and central bank chiefs continue their meeting on Sunday which was expected to wrap up with a final statement around 4:00pm local time (2200 GMT).
The row over fighting the debt crisis threatened to overshadow a broader discussion on implementing structural reforms to boost economic growth in the global economy.
Geithner called on Europe to build a "strong, more credible firewall" while the head of the OECD appealed for what he termed "the mother of all firewalls" to protect the eurozone crisis from spilling over into the rest of the world.
EU leaders at a summit next week in Brussels are expected to address the thorny issue of raising its bailout fund.
Several countries both inside and outside the 17-nation bloc have suggested combining the current rescue fund, the EFSF, with the more permanent ESM version that comes into effect in July.
This would give the eurozone a war chest of around 750 billion euros ($1 trillion) to douse, if needed, further fires from the likes of Portugal, Spain or Italy.
However, Germany has rejected all appeals to pour more funds into the pot, with Finance Minister Wolfgang Schaeuble dismissing the proposals in no uncertain terms just hours before the meeting began.
"Let me be clear: it doesn't make any economic sense to follow the calls ... for endlessly pumping money into the rescue funds nor setting up the ECB printing press," Schaeuble told a business reception here.
The other main topic here was a discussion about handing the International Monetary Fund more resources to deal with a string of bailouts caused by the economic crisis.
IMF chief Christine Lagarde has issued an appeal to the lending body's members for some $500 billion in additional funds.
However, key players such as Japan and the UK have insisted that the eurozone dips its hand into its own pocket before they commit taxpayers' funds to the crisis.
Progress on this was set to stall at this meeting, with a decision more likely at a leaders' summit in June.