The Iranian foreign ministry on Tuesday denied US accusations that three al-Qaeda operatives were in Iran, helping to move money and weapons around the middle-east, state media reported.
The US treasury announced sanctions on Wednesday against the three senior al-Qaeda members, saying they were based in Iran and had key logistical roles for the group.
But Bahram Ghasemi, Iran's foreign ministry spokesman, said there was no knowledge of their whereabouts.
"The Islamic Republic of Iran has no information of the presence of these people on its territory," he told IRIB state television.
"The US administration, instead of issuing general statements, should in practice enable a coordinated international fight against terrorist groups by sharing precise information."
"Iran continues its strong determination in fighting terrorist groups," he added.
The US treasury named the three alleged operatives as Faisal Jassim Mohammed al-Amri al-Khalidi, Yisra Muhammad Ibrahim Bayumi and Abu Bakr Muhammad Muhammad Ghumayn.
It said Khalidi, a 31-year-old Kuwait-born Saudi national, was "part of a new generation" of Qaeda operatives who in May 2015 participated in a senior leadership meeting as the military commission chief.
Egyptian Bayumi, 48, is a Qaeda veteran involved recently in raising and deploying funds for the group.
Ghumayn, a 35-year-old Algerian, took control of the financing and organisation of Iran-based Qaeda members last year, the Treasury said.