US Secretary of State Hillary Clinton sought to reassure Asian investors over US debt worries on Monday, saying she was confident President Barack Obama would ultimately reach a deal with congressional leaders to prevent a catastrophic default.

 "I'm confident that Congress will do the right thing and secure a deal on the debt ceiling, and work with President Obama to take the steps necessary to improve our long-term fiscal outlook," Clinton said in a speech to business leaders in Hong Kong.

Clinton's speech was overshadowed by Washington's failure thus far to craft a deal to extend the US government's borrowing authority, but she said the political wrangling over spending was both natural and healthy.

 "Let me assure you we understand the stakes. We know how important this is for us and how important it is for you," Clinton said.

US lawmakers failed to achieve a budget breakthrough on Sunday, with scant sign of a possible deal to raise the government's debt ceiling and head off a default in nine days that could trigger global economic calamity and downgrade America's triple-A credit rating. After weeks of rancorous talks, both sides appeared further apart than ever on a deficit reduction deal that would clear the way for Congress to raise the $14.3 trillion debt ceiling.

Clinton laid out the US vision for the future of world trade, one she said must be based on "open, free, transparent and fair" principles that apply to all.

"We in the United States are in the middle of a necessary transition. We must save more and spend less...we must borrow less as well," Clinton said.