In remarks to commanders of the Islamic Revolutionary Guard Corps, Ayatollah Ali Khamenei said a 10-year renewal of U.S. sanctions on Tehran's energy, banking and defense sectors, which the House approved this month, would violate the nuclear deal struck between Iran and world powers last year.
"The current U.S. government has breached the nuclear deal in many occasions," Khamenei said, according to remarks published on his website. "The latest is extension of sanctions for 10 years, that if it happens, would surely be against JCPOA, and the Islamic Republic would definitely react to it."
Khamenei's statement capped a string of remarks by senior Iranian officials in recent days, all of them warning that Iran will retaliate in some fashion if sanctions are extended and that such a move could spell the end of the nuclear agreement, officially known as the Joint Comprehensive Plan of Action.
Ali Shamkhani, secretary of Iran's Supreme National Security Council, addressed U.S. officials directly Tuesday night. "If you extend the sanctions, this will mean kicking the JCPOA away, and we will confront it through implementing powerful technical packages," he said, according to state-run television.
The warnings put President Obama in a tough spot as Congress prepares to pass the 10-year extension of sanctions that lawmakers in both parties have long been clamoring for.
Congressional leaders are also pledging to expand on those sanctions next year with a broader spectrum of punitive measures, including sanctions to address Iran's recent spate of ballistic missile tests, as well as cyberthreats and cyberespionage activities.
But the White House has resisted the changes — and has not indicated yet whether it will sign off on even the renewal of existing sanctions, which would otherwise expire at the end of the year.
The White House has long argued that the extension of the Iran Sanctions Act is not necessary, as the president has the authority to sanction Iran without the assistance of Congress.
"If Congress wants to put more [sanctions] on the table, then we'll take a look at what they propose," White House spokesman Josh Earnest told reporters on Tuesday. "We certainly are not going to, however, sign a piece of legislation that would undermine the ability of the international community to continue to successfully implement the international agreement to prevent Iran from obtaining a nuclear weapon."
The White House maintains that a renewal of the ISA would not, by itself, violate the nuclear deal as it is simply a continuation of sanctions already on the books. Still, the administration has not taken the possibility of an Obama veto off the table.
But even if the president were to exercise his veto authority, he may be unable to prevent an extension of the existing sanctions. Lawmakers on both sides of the aisle have been frustrated with the White House's responses to Iran's more aggressive moves, and if senators vote like their counterparts in the House did, Congress will be able to override Obama's veto.