The open letter, drafted by freshman Arkansas senator Tom Cotton and addressed to "leaders of the Islamic Republic of Iran," declared that any deal reached by multinational negotiators without congressional approval could be undone by the next president "with the stroke of a pen."
Iranian Foreign Minister Mohammad Javad Zarif, who has been negotiating directly with U.S. Secretary of State John Kerry in Geneva on a nuclear deal, had earlier dismissed the letter as "mostly a propaganda ploy."
On Wednesday, Kerry told a Senate Foreign Relations Committee hearing that he greeted the letter with "utter disbelief," calling it a breach of "more than two centuries of precedent" and factually incorrect.
In his first reaction, Khamenei, who has the last word on policy in Iran, said countries typically honor their international commitments even if governments change, "but American senators officially announced the commitment will be null and void after this government leaves office. Isn`t this the ultimate degree of the collapse of political ethics and the U.S. system`s internal disintegration?"
"Of course I am worried, because the other side is known for opacity, deceit and backstabbing," he said. "Every time we reach a stage where the end of the negotiations is in sight, the tone of the other side, specifically the Americans, becomes harsher, coarser and tougher. This is the nature of their tricks and deceptions."
But, the supreme leader told a meeting with President Hassan Rouhani and senior clerics, "Iranian officials know what they are doing."
Negotiators from Iran and the U.S., France, Britain, Russia, China and Germany have set a deadline of late March for reaching a framework agreement and July for a final accord.
Iran has insisted on the right to maintain a civilian nuclear power program, but has denied allegations by some Western nations that it is attempting to build a nuclear weapon.
Khamenei also took a none-too-subtle swipe at Israeli Prime Minister Benjamin Netanyahu, referring to a "Zionist clown" who recently addressed Congress to oppose what he said were elements of the emerging deal.
Ayatollah: GOP letter signals `disintegration` in D.C.
12 March 2015
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Ayatollah Ali Khamenei, Iran`s supreme leader, said Thursday that a letter signed by 47 GOP senators warning that the next U.S. president could scrap any nuclear deal with Tehran is a sign of "disintegration" in Washington, according to Iranian news agencies.
