TEHRAN, Young Journalists Club (YJC) - "What Secretary Kerry has done is unseemly and unprecedented," Pompeo told a news conference, adding that he "ought not to engage in that kind of behavior", Reuters reported.
“It is inconsistent with what the foreign policy of the United States is, as directed by this president. It is beyond inappropriate," Pompeo deplored.
Pompeo's criticism of Kerry came a day after US President Donald Trump accused the former secretary of state of "illegal" meetings on Iran in a late-night tweet.
Kerry, in a radio interview with Fox News as part of a book tour, said he had met with Iranian Foreign Minister Mohammad Javad Zarif "three or four times" since the end of his term in January 2017. He has also accused the Trump administration of pursuing a policy of regime change in Iran.
"Mr. President, you should be more worried about Paul Manafort meeting with Robert Mueller than me meeting with Iran's FM," Kerry said on Twitter shortly after Pompeo's remarks, referring to Trump's former campaign chairman who on Friday agreed to cooperate with federal investigators into Russian meddling in the 2016 US election.
"There’s nothing unusual, let alone unseemly or inappropriate, about former diplomats meeting with foreign counterparts," a spokesman for Kerry said in a statement. "What is unseemly and unprecedented is for the podium of the State Department to be hijacked for political theatrics," he said.
During interviews this week, Kerry has accused the Trump administration of pursuing a policy of regime change in Iran.
Pompeo pushed back, saying that was not the administration's intention.
"This is a former secretary of state engaged with the world's largest state sponsor of terror...," Pompeo said, adding, "He was telling them to wait out this administration. You can't find precedent for this in US history," Pompeo noted.