It has been reported through a series of memoirs that once a US agent brought a message from the then US president Jimmy Carter for Imam Khomeini.
The US agent and representative said that “you must follow Shapour Bakhtiar” who was an Iranian politician who served as the last prime minister of Iran under the rule of the Shah regime.
The agent issued threats that if Imam doesn’t follow their advice what could happen and consequences.
The message was conveyed to Imam during his stay in exile in Paris.
Imam ignored his threat and said that Carter must know that until now I have contained my people in Iran and if I ask them what they can do is beyond the US president’s imagination.
The incident happened some months before Imam returned to his homeland leading the Islamic Revolution to victory in 1979.
Extracted from the late Haj Seyyed Ahmad Khomeini, impressions of Imam's biography, volume 4, page 208