Iran's top diplomat fires back at Republican senator's 'macho personal smear' on Twitter

Iranian foreign minister Javad Zarif did not take kindly to Sen. Tom Cotton's (R-Arkansas) aggressive tweets challenging him to a debate. 

On Thursday, Zarif wrote on Twitter that Cotton had attacked him with "macho personal smear." The Iranian official also suggested Cotton should be concerned about the "peace" of his son Gabriel, who was born Monday night:

This particular back-and-forth started with a question submitted from Business Insider the day before.

Asked about negotiations with President Barack Obama's successor, Zarif warned that there would be "chaos" if the next president tried to undo an executive agreement with Iran that rolls back sanctions in exchange for Tehran curbing its nuclear program. 

Zarif added in a shot at Cotton, who was the lead signatory on a high-profile open letter to Iran's leadership. The letter informed them that Obama's successor could easily reverse any nuclear agreement not approved by Congress. 

"You know that, maybe Sen. Cotton doesn't, but you know that 90% of US overseas agreements are executive agreements," Zarif said.

Cotton responded by firing off a series of tweets challenging Zarif to a constitutional debate:

This was not the first time Cotton and Zarif have battled over Twitter. Zarif, a US-educated and media-savvy official, previously shot barbs at Cotton's Farsi translation of his open letter.

Zarif not-so-subtlely informed him, via tweets, that he speaks English just fine.