US Treasury Secretary John Snow put the ball squarely in Congress' court on the debt ceiling issue, warning lawmakers the US government could not be financed past November unless they act to raise the limit.

In a letter sent to Capitol Hill leaders, Mr Snow said the debt subject to the current $7.384 trillion limit will be hit around late September or early October. Even if the government takes certain accounting maneuvers to stay beneath the ceiling, as it has done in the past, Mr Snow said, "we can finance government operations no longer than mid-to-late November 2004".

Mr Snow has been saying informally for months now that Congress needs to raise the debt ceiling, which would be the third such hike under the Bush administration.

"As you know, the 'full faith and credit' of the United States is a unique asset that underlies the leadership position of our nation in world capital markets. A failure to increase the debt limit in a timely manner would threaten this position," Mr Snow said in the letter.

The national debt, which stood at $7.271 trillion on Friday, is the sum of past annual budget shortfalls plus special Treasury securities issued to government trust funds for programs such as Social Security.

Raising the debt ceiling is often a politically tricky battle, as the "must pass" nature of the legislation leads some lawmakers to try to attach otherwise unpopular items to it. Also, Democrats would likely use the issue to highlight the record budget deficit seen in 2003 under President George W. Bush and an even larger one expected this year.

Earlier this year, the House of Representatives backed a plan that would have led to a debt ceiling increase, but the Senate, under pressure from Democrats, rejected the measure.

While failing to raise the debt ceiling could lead to an eventual default on government debt, that outcome is unlikely. Treasury has taken accounting maneuvers in the past to raise money outside the limit and would likely do so again, if needed. Also, lawmakers have never allowed a default in the country's 228-year history.