IIRC they are trying to pay off their debt since they are on a brink of default. They don't want to borrow anymore.
The massive tax cuts Trump is trying to extend or introduce are much larger than the spending cuts proposed so far.
edit: Also the USA is nowhere near a default, unless congress chooses to not raise the ridiculous debt ceiling policy.
They are literally borrowing more right now. I believe at record levels. Billions per day.