The United States accused Iran of having a “secret deal” with al-Qaida as Washington announced sanctions Thursday on six suspected al-Qaida operatives.

The Treasury Department did not offer many details. But it says the operatives are part of a network headed by Ezedin Abdel Aziz Khalil, described by U.S. officials as an al-Qaida facilitator based in Iran.

The Treasury statement says Khalil has been operating under an “agreement” between the Iranian government and the terror group.

The department says Iran is a “critical transit point” for funding to support al-Qaida's activities in Afghanistan and Pakistan.

There was no immediate reaction from the Iranian government.

But Treasury Under Secretary David Cohen says a “secret deal” in which Iran allows al-Qaida to funnel resources through its territory has been exposed. He says the case illuminates what he called another aspect of Tehran's “unmatched support for terrorism.”

The sanctions on Khalil and the five other reputed operatives freeze any U.S. assets that they may have and prohibit U.S. citizens from engaging in financial transactions with them.