Washington  - US President Barack Obama said Wednesday that reforming the country's costly health care system was the only way to reduce a budget deficit that is running at record levels.

In an evening press conference, Obama again stressed the urgency of reining in health costs. He renewed pressure on legislators who have been stuck for weeks in difficult negotiations over how to overhaul the system.

"The American people are understandably queazy about the huge deficits and debts we're facing right now," Obama told reporters at the White House.

Obama said the current federal deficit - projected to hit 1.8 trillion dollars or nearly 13 per cent of economic output this year - was necessary to combat the worst economic crisis since the Great Depression.

Other countries, most notably China, have expressed concern that Obama's administration has not offered a viable plan for cutting that deficit over the long term.

Obama insisted health care was key to that long-term plan: ""We're also gonna have to change health care, otherwise we can't close that (budget) gap."

US politicians have been locked in furious debate over whether the health reform plans before Congress - designed to cut costs and cover about 47 million Americans that currently have no health insurance - will actually raise or lower the federal deficit.

The US health care system is already the most expensive in the industrialized world, and Obama insisted he would not sign a piece of legislation that raised costs further.

"Health care reform is not gonna add to that deficit. It's designed to lower it," he said. (dpa)