India's Prime Minister called on the G20 yesterday to send a strong warning against protectionism this week as world leaders seek to shore up a tentative global recovery and prevent future economic crises.

G20 host nation the United States slapped tariffs on Chinese-made tyres earlier this month, reviving fears of a tit-for-tat round of protectionist measures that risk strangling trade and plunging the global economy back into recession.

"We would also like to see a strong message to emerge from Pittsburgh against protectionism in all its forms, whether trade in goods, services, investment or financial flows," Manmohan Singh said in a statement before leaving for today's summit of top industrialised and emerging nations.

Mr Singh said the global economy and financial markets have shown an improvement since G20 summits earlier this year, but said the economy was "still not out of woods".

Washington has scoffed at the idea of a budding trade war, while pushing a plan for G20 nations to build a more balanced global economy that would be less prone to painful boom and bust cycles.

British Prime Minister Gordon Brown said on Tuesday there was substantial backing among the group for creating a new framework to shrink surpluses run by top exporters such as China while cutting ballooning deficits in others.

But such a plan would ultimately need to convince consumers in debt-laden nations including the US to save more and buy less, which would be a tall order. And such a process would almost certainly require an even weaker US dollar, which fell to one-year lows yesterday. China is likely to agree publicly with the broad aim of a new framework, especially if it gives emerging nations more clout on the world stage, but is expected to resist any sweeping reforms that could threaten its robust growth. It is also expected to brush off any calls from the West to let its tightly controlled yuan currency move more freely.

It is also unclear whether Germany and Japan, two other big exporters, would back the US proposal, and how such a plan would be implemented and enforced.

Brazil, one of the emerging heavyweights of the developing world, spoke out against the US proposal, saying the IMF already played a role in monitoring economies and calling Washington's plan "obscure".

While the G20 meeting may signal another step in a long-term global power shift, investors will focus on clues on how the US and leading European nations plan to wind down massive emergency stimulus programmes without destabilising economies again.

"We believe that some level of global coordination is likely in the quarters ahead. This is particularly for central bank exit strategies which may be coordinated so as not to trigger adverse currency movements," Glenn Maguire, Societe Generale's chief Asia economist, said in a note.

"Yet, we remain sceptical on the ability to put into place a more rigid framework that would enforce a new economic world order," Mr Maguire said.