Kerry also said that he thought Trump should have stayed in the Iran deal, arguing that under the deal "you have China, Russia, these other countries with you in the effort to leverage this different behavior from Iran rather than unilaterally pulling out and isolating yourself and making it much more hard to sit down with any Iranian".
"John Kerry had illegal meetings with the very hostile Iranian Regime, which can only serve to undercut our great work to the detriment of the American people".
"He told them to wait out the Trump Administration!" he said, ending his Tweet with the word "BAD!"
In his tweet, Trump asked whether Kerry had complied with the Foreign Agents Registration Act.
The Foreign Agents Registration Act (FARA) is a disclosure statement that requires a person acting as an agent of a foreign principal in a political or quasi-political capacity to make public disclosure of their relationship with the foreign principal. Also unclear is whether any Iranians specifically asked Kerry for advice. "John Kerry can't get over the fact that he had his chance and blew it!"
"When I met with the Iranians, the policies of the United States was still to be in the Iran deal because the president had not decided and not pulled out", Kerry said.
A Kerry spokesperson did not immediately respond to Fox News' request for comment on the president's tweet.
Trump withdrew the United States from a nuclear deal with Iran that Kerry negotiated between Iran and six world powers in 2015.
U.S. Secretary of State Mike Pompeo speaks during a news conference at the ASEAN Foreign Ministers' Meeting in Singapore August 4, 2018. He has also accused the Trump administration of pursuing a policy of regime change in Iran. A third is reported to have occurred at the United Nations headquarters, which is not technically on USA soil. In return, Iran agreed to restrictions on its nuclear program making it impossible to produce a bomb, along with rigorous inspections. "And I've also seen reports that he is apparently providing, according to reports, advice to the Iranian Government".
"The best advice that he should be giving the Iranian government is to stop supporting terror groups around the world".
Kerry said such meetings are appropriate, later explaining during a television interview on Fox News that "every secretary of state, former secretary of state continues to meet with foreign leaders, goes to security conferences, goes around the world".
However, Kerry made it clear in the interview that his intention was not to "coach" Iran on how to manage Trump's rejection of the deal. You know, how does one resolve Yemen? "What I have done is tried to elicit from him (Zarif) what Iran might be willing to do in order to change the dynamic in the Middle East for the better".