The interim deal calls for Tehran to freeze parts of its nuclear program for six months in exchange for an easing of some Western economic sanctions. During this interim period, both sides agreed to try to reach a permanent deal to end Iran's nuclear threat.
In an interview Saturday with Time, Zarif warned the United States against adopting any sanctions against Iraq during the negotiating process. If they do, "the entire deal is dead," he said.
"We do not like to negotiate under duress. And if Congress adopts sanctions, it shows lack of seriousness and lack of a desire to achieve a resolution on the part of the United States."
Zarif said wariness of the pact within Iran's Parliament "emanates from the lack of trust because we do not have a past on which we can build."
"It's a psychological barrier to interaction that we need to overcome. The fundamental reason for opposition: they believe the West and particularly the United States are not sincere, are not interested about reaching an agreement," Zarif said in Saturday's interview in Tehran.
Zarif said some of the statements coming out of Washington "give them every reason to be concerned."
"Now we know that Washington is catering to various constituencies and is trying to address these various constituencies," he said. "We read their statements in the light of their domestic constituency process. But not everybody in Iran does that. We believe that the U.S. government should stick to its words, should remain committed to what it stated in Geneva, both on the paper as well as in the discussions leading to the plan of action."
Israeli Prime Minister Binyamin Netanyahu Sunday said a permanent nuclear deal with Iran must contain a vow Tehran will end anti-Israel threats and stop backing anti-Israel militants.
Netanyahu made the demand to the Brookings Institution's Saban Center for Middle East Policy as expert-level negotiators from Iran and the United States, Britain, France, China, Russia and Germany -- the six world powers overseeing an interim agreement worked out in Geneva, Switzerland, last month -- were preparing to meet Monday to discuss inspections of Iran's nuclear facilities.
International Atomic Energy Agency inspectors reporting to the United Nations Sunday visited a heavy-water Iranian nuclear production plant made available for inspection under the Nov. 24 interim deal.
"[Iran] is committed to our annihilation, and I believe that there must be an uncompromising demand at the Geneva talks for a change in Iran's policy," Netanyahu told the Washington forum in a live video link from Jerusalem.
"In other words, there needs to be not just a change in the capability of Iran to arm itself, but also a change in its policy of genocide," he said.
U.S. and European officials have said the Geneva talks are focused only on the nuclear issue, viewing Iran's possible nuclear-weapons development as the most serious threat to Israel and the international community.
Iran denies it has nuclear-weapons intentions.
But Tehran has made repeated threats to destroy Israel. It also supports Lebanese and Palestinian militant groups fighting Israel.
President Barack Obama told the Saban Forum Saturday he believes Netanyahu should give the Geneva accord time to succeed, even while acknowledging he he thinks it has just a 50-50 chance.
"Presuming that it's going to be a bad deal and, as a consequence, not even trying for a deal I think would be a mistake," Obama said.
Netanyahu told the annual forum of government officials, academic researchers, journalists and business leaders Sunday he agreed with Obama "a diplomatic solution is better than a military solution."
"While Israel is prepared to do what is necessary to defend itself, we share President Obama's preference to see Iran's nuclear weapons program end through diplomacy," he said.
At the same time, Netanyahu also linked international efforts to deny Iran an atomic bomb to Israel's support for the Middle East peace process.
"Our best efforts to reach Palestinian-Israeli peace will come to nothing if Iran succeeds in building atomic bombs," Netanyahu said in remarks quoted by the Wall Street Journal.
"A nuclear-armed Iran would give even greater backing to the radical and terrorist elements in the region. It would undermine the chances of arriving at a negotiated peace. I would say it would undermine those peace agreements that we have already reached."