The New Yorker magazine reported on Friday that Senator Rand Paul met Zarif in the US on July 15 and had Trump's blessing when he extended an invitation to the Iranian minister to go to the White House.
Officials in Iran confirmed the report on Sunday, heaping scorn on the Trump administration for claiming to want dialogue with Iran while slapping sanctions on its top diplomat.
"For a government to constantly claim (to favor) negotiations and afterward sanction the foreign minister... if this is not ridiculous, then what is it?" said government spokesman Ali Rabiei.
"In a meeting with a senator, he (Zarif) is invited to come to a meeting and then he is sanctioned," Rabiei said in remarks aired on Iranian television.
"We believe that these sanctions show that the politicians of the White House have to some extent made a personal issue of affairs," he said, describing such behavior as "childish".
Rabiei said the US forfeited its right to diplomatically engage Iran by targeting Zarif.
He stressed that “attacking” Zarif with the sanctions equaled “attacking the foundations of the Iranian nation-state.”
“America shall know that in the opinion of the government of the Islamic Republic of Iran, Zarif is [Iran’s] chief of foreign policy, chief of public diplomacy, and chief of security diplomacy, and that all diplomatic pathways must go through him.”
On Wednesday the United States imposed sanctions against Zarif, effectively slamming the door on Iran's top diplomat.
Rear Admiral Ali Shamkhani, the secretary of Iran's Supreme National Security Council, said the invitation and sanctions amounted to a failure of US diplomacy.
"Imposing sanctions on the honorable foreign minister of Iran after the refusal of Trump's proposal for face-to-face talks with him showed the 'maximum pressure' train has stopped at the 'failure station'," he said in a statement.
Tensions between arch-enemies Iran and the United States have soared after Washington stepped up its campaign of "maximum pressure" against the Islamic Republic by withdrawing from a landmark nuclear deal between Iran and world powers and reimposing biting sanctions against the country last year in May.
At the height of the crisis, Trump called off airstrikes against Iran at the last minute in June after the Iranian forces shot down a US spy drone.
According to The New Yorker, Zarif said it was up to Tehran to decide on accepting a meeting with Trump.
Zarif told the magazine he would not want a White House meeting that yielded just a photo opportunity and a two page statement afterward, it reported.
Trump has said publicly several times that he is willing to hold talks with the Iranians even as he lambasts Tehran as a threat to regional security and US interests.
Iranian President Hassan Rouhani has said the country will sit down for talks if the US lifts all sanctions it reimposed on Iran.