Iran gained access to about $100 billion in frozen assets when an international nuclear agreement was implemented last month, but $50 billion of it already was tied up because of debts and other commitments, a US official said on Thursday.
Stephen Mull, the State Department's lead coordinator for implementing the international nuclear agreement with Tehran, also told the House Foreign Affairs Committee there was no evidence Iran had cheated in the first few weeks since the deal was implemented.
Mull and John Smith, acting director of the Treasury Department office that oversees sanctions, faced heated questioning from some members of the committee, where several Democrats had joined Republican lawmakers in opposing the nuclear pact that was reached in July.
Many have worried that Iran would cheat on the deal and use unfrozen funds for action against Israel or to support Islamist militants elsewhere in the region.
"Of that amount, a significant portion of it, more than $50 billion, is already tied up," Mull said.