The U.S. Treasury Department on Monday said it plans to borrow more in the third quarter than it had previously forecast.

In a statement, the Treasury said it would borrow $433 billion during the July-September quarter, about $274 billion more than its previous estimate, assuming an end-September cash balance of $350 billion. It said the increase in borrowing was driven primarily by changes in cash balance assumptions.

In April, the Treasury said it expected to issue $160 billion in net marketable debt in the July-September period.

The Treasury said it expects to borrow $381 billion during the October-December quarter, assuming an end-December cash balance of $410 billion.

It borrowed $40 billion through credit markets in the April-June quarter, ending the period with $264 billion in cash.

Additional details of the Treasury's quarterly refunding will be announced at 8:30 a.m. (1230 GMT) on Wednesday.

A Treasury official who asked not to be identified said $271 billion of the increase in the third quarter reflected changes in cash balance assumptions.

The Treasury's announcement comes as the U.S. Congress debates legislation backed by President Donald Trump that would accelerate rising federal budget deficits and suspend limits on Washington's borrowing powers over the next two years.

The House of Representatives passed the legislation on Thursday. The Senate is expected to debate the measure this week.

The Treasury official said the borrowing expectations assumed the debt limit would be suspended, allowing the Treasury to raise enough cash to achieve cash balances it deemed prudential.

Failure to lift the limit on federal borrowing could leave Washington unable to pay all its bills in early October, according to projections by the Bipartisan Policy Center.

The U.S. fiscal position has deteriorated since 2016, with Washington running nearly $1 trillion into the red in the 12 months through July.