WASHINGTON – The federal government faces exploding deficits and mounting debt over the next decade, White House officials predicted Tuesday in a fiscal assessment far bleaker than what the Obama administration had estimated just a few months ago.

Figures released by the White House budget office foresee a cumulative $9 trillion deficit from 2010-2019, $2 trillion more than the administration estimated in May. Moreover, the figures show the public debt doubling by 2019 and reaching three-quarters the size of the entire national economy...