US PRESIDENT Barack Obama came under fire on Saturday from Asia-Pacific leaders for backsliding on free trade at a regional summit devoted to driving the world economy out of crisis.

'President Obama is facing severe political constraints that run counter to free trade,' Mexican President Felipe Calderon said, complaining about US foot-dragging on full implementation of the Nafta pact for North America. 'The cruel paradox is that within a global economy, what really kills companies is inefficiency and lack of competition. Therefore protectionism is killing North American companies.

'So I think this has to do with the fact that the US government is under strong political pressure that really is not being counteracted from the political perspective' of the Obama administration.

The US Congress has turned even more sour on free trade after the worst economic crisis since World War II. One landmark pact with South Korea is languishing and critics say the White House has done little to revive it.

The US economy is perking up but unemployment has breached 10 per cent and economic leaders, including the heads of the International Monetary Fund and World Bank, warned in Singapore that protectionism could choke off recovery.

Russian President Dmitry Medvedev said controversial tariffs enacted by his government to shore up ailing industries were temporary and urged his regional colleagues to 'do anything we can to refrain from protectionism in any sphere'. -- AFP