The dollar value of support to this will grow, exponentially as time passes. The government doesn't just open their wallet and hand out the rent money. The American people who actually keep up would have a cow if we just pledged a bunch of cash with no accountability over where it comes from.
It is a Chinese fire drill to rearrange obligated funds. Without going through the Google and Email drill, I'm guessing that initial support comes from contingency funds set aside, possibly through State foreign development resources, and the bean counters will work out the details of rest.
Somewhere, out there, are one or more DoD execution orders that have fund realignment-reimbursement wording worked into them. They are most likely being directed to draw on operational funding as far as managing accounts for right now, while maintaining a separate accounting for what is actually spent in this effort. Somewhere along the way, funds will get transferred from account "A" to account "B".