SINGAPORE, (AFP) - The United States will push its economic interests more aggressively to preserve its global leadership after being tied down by two wars in the past decade, Secretary of State Hillary Clinton said Saturday.

"We are shaping our foreign policy to account for both the economics of power and the power of economics," she said in a speech in Singapore en route to an Asia-Pacific summit in Cambodia to be attended by President Barack Obama.

After a decade attending to "a war in Iraq that is now over and a war in Afghanistan that is winding down," Clinton said the "first and most fundamental task is to update our foreign policy and its priorities for a changing world".

"Our global leadership depends on our economic strength," she said, adding that the emphasis on "jobs diplomacy" would boost US exports, open up new markets and level the playing field for American firms to compete overseas.

More than 270 US embassies and consulates across the world will operate as advocates for US companies and help achieve Obama's goal of doubling US exports in five years, Clinton said.

Washington is seeking "a rebalancing of the global economy so Americans export more, Asians import more and we avoid financial crises and build middle classes".

"Responding to threats will of course always be central to our foreign policy, but it cannot be our foreign policy. America has to seize opportunities that will shore up our strength for years to come," Clinton said.

Even non-military powers are gaining clout "less because of their size of their armies than because of the growth of their GDP".

"For the first time in modern history, nations are becoming major global powers without also becoming global military powers," she added, citing the example of Singapore, a city-state whose two-way trade with the United States now exceeds $50 billion.

Clinton sought to allay Asian concerns over a looming "fiscal cliff" of tax hikes and budgets cuts pitting the newly re-elected Obama against Republican opponents in Congress, raising fears of a new US recession if they fail to strike a compromise.

"Let's be clear: the full faith and credit of the United States should never be in question. Today, as Washington gears up for another round of budget negotiations, I'm again hearing concerns about the global implications of America's economic choices," she said.

"Now, I'm out of politics, but let me assure you that for all the differences between the political parties in my country, we are united in our commitment to protect American leadership and bolster our national security. Reaching a meaningful budget deal is critical to both."