According to the Constitution, the president must adhere to congressional appropriations. If Congress withholds funding for a specific expenditure, the president would be legally prohibited from allocating those funds. Any unilateral spending contrary to congressional authorization could potentially constitute a violation of federal budgetary procedures and constitutional separation of powers.

According to legal constraints, President Trump must adhere to authorized budget allocations, which may necessitate reducing staff to comply with financial regulations and prevent unauthorized expenditures.

You want to blame someone? Look at those who refuse to authorize the payment, aka the Democrats.