Foreign policy is under the control of the executive branch. The President can order a pause on foreign aid to allow the new administration to review all foreign aid.
Once those orders were ignored, the administration had to take more drastic steps (as SOS Rubio pointed out).
No, the President cannot just unilaterally ignore Congressional spending requirements just because "the executive controls foreign policy". That's what got him impeached the first time.
They're also not "pausing" shit, they're cancelling contracts effective immediately & locking up the buildings. Elon tweeted a picture of the sign being removed from the front of the building. You're being dishonest about what is going on.
Once those orders were ignored, the administration had to take more drastic steps (as SOS Rubio pointed out).