Zarif said the political battles had become so tense it had thrown his back into spasm. He said the source of his distress was an article in the hardline newspaper Kayahan daily, which Zarif claimed misquoted him as saying the recent telephone call between the Iranian president, Hassan Rouhani, and his US counterpart, Barack Obama, had been inappropriate.
The stress this alleged misrepresentation, said Zarif, drove him to seek medical attention.
"I got pain in the back and foot after seeing the newspaper's headline this morning," Zarif said then on his Facebook page.
Rouhani's short-term priority is to negotiate an easing of western sanctions as part of negotiations over Iran's nuclear program. Talks in Geneva adjourned Tuesday until Wednesday after Iran presented what it said was potentially a breakthrough proposal designed to diminish international fears that Tehran wants nuclear weapons.