US budget deficit for 2015 falls to $439 billion

Gains in tax revenue outpaced greater government spending

The US budget deficit for 2015 has fallen to its lowest level in eight years, spurred by gains in tax revenue that outpaced greater government spending.

The Treasury Department says the deficit in the just-completed 2015 budget year fell to $439 billion from $483 billion in 2014. It is equal to 2.5% of the economy, the smallest proportion since 2007, and below the average of the past 40 years.

The figures come as budget battles in Washington are intensifying.

Congress and the White House face an early November deadline to raise the nation's borrowing limit. Lawmakers are also seeking a separate agreement with the Obama administration on a budget to keep the government open past a December 11 deadline.