Iran hasn’t received any of the $6 billion in frozen assets the US pledged to dole out in exchange for progress made implementing the US-Iran memorandum of understanding, a US administration official said on Tuesday, luring Iran back to the negotiating table in Qatar, the New York Post reports.

“No frozen funds have been released and no frozen funds will be released unless Iran meets the requirements outlined in the MOU,” the person said. “…Nothing is given for free and everything is tied to benchmarks.”

While Iran has argued the funds should be delivered in a lump sum, the US intends to make small, incremental payouts—directly to vendors—as Iran progresses in key negotiation areas, the US official said.

Iranian President Masoud Pezeshkian on Monday said that Iran and Qatar had agreed to unfreeze $6 billion of the total $12 billion in Iranian assets in Qatar. Pezeshkian noted that the work necessary to return the remaining portion of those funds was also in progress.