Congress is charged with crafting the government budget and largely ignored Trump's recommendations when it passed a continuing resolution to temporarily fund the government earlier this year. But in a pre-emptive strike on Wednesday, the White House wrote on Twitter: "Faulty Numbers = Faulty Results".
By contrast, CBO's analysis of Trump's budget plan shows the deficit steadily rising from $593 billion in fiscal 2018 to $720 billion in fiscal 2027.
In fiscal 2016, the deficit was $585 billion, while the CBO expects it to grow to $693 billion for the 2017 fiscal year.
Congress ultimately gets to approve a budget for Trump's signature, which means numerous White House's priorities may not end up in the final budget.
The White House projected its budget would lead to 3% annualized economic growth, as many economists noted at the time using some funky math to get there.
"Today's CBO report makes clear just how far the President's budget is from balance", said Maya MacGuineas, president of the Committee for a Responsible Federal Budget, in a statement.
The CBO said did not take into account all of Trump's proposals that may affect the economy because "the details on numerous proposed policies are not available at this time". Its projections included a $2 trillion math error, claiming the amount would be spent twice on balancing the budget and tax cuts.
On Thursday, the White House's Office of Management and Budget found parts of the budget office's work worthy of praise.
Mulvaney said that discussion continues among House lawmakers about fashioning a package of cuts from so-called mandatory programs that can win support from both conservative and centrist Republicans.
When President Trump released his 2018 budget proposals - marked by trillions in spending cuts - the White House claimed it would balance the budget in a decade. Instead, it estimates that Trump's budget would reduce deficits by a third over the next decade relative to where they would be otherwise.