Just eight minutes after President Barack Obama wrapped up a White House press conference he called on Wednesday to defend a day-old nuclear deal with Iran, the Islamic republic’s supreme leader used Twitter to tweak him. In a short letter to Obama that he posted on Twitter, Ayatollah Ali Khamenei wrote that it’s partner nations like China and Russia who should be watched carefully – not Iran – to make sure they honor the terms of the landmark bargain.

‘You are well aware that some of the six states participating in negotiations are not trustworthy at all,’ Khamenei wrote in a stunning rhetorical act of jiu-jitsu. The agreement, signed by Iran, the U.S., Russia, China, France, the United Kingdom, Germany and the European Union, seeks to limit Tehran’s aggressive nuclear program in exchange for dropping a series of crippling economic sanctions. American opponents of the arrangement, which still has to earn approval from Congress, have complained that Iran can’t be trusted to hold up its end by dramatically scaling back its uranium mining and processing, and starving for a decade what was thought to be a robust but covert nuclear weapons program. MORE