Iranian Foreign Minister Mohammad Javad Zarif and Russian Foreign Minister Sergei Lavrov attend a news conference at the United Nations in Geneva, Switzerland, Oct. 29, 2019. Photo: Reuters / Denis Balibouse.

The United States will not accept new Russian demands for an exemption to Western sanctions as part of a nuclear deal with Iran, a senior State Department official told The Wall Street Journal.

Washington and its allies imposed far-reaching sanctions on Moscow following its invasion of Ukraine, causing serious damage to the Russian economy.

Russian Foreign Minister Sergei Lavrov inserted a new requirement into the nuclear agreement being negotiated in Vienna on March 5, asking the Biden administration for guarantees that US sanctions will not impact “our right to free, fully-fledged trade and economic and investment cooperation and military-technical cooperation with Iran.”

Russia’s ambassador at the Vienna talks, Mikhail Ulyanov, reiterated Lavrov’s demand last Thursday. “We believe that all our trade and economic relations with Iran should be exempt from current or future EU or US sanctions,” he told reporters.

A senior US State Department official told the Journal on Sunday that if Moscow does not back down on its demands, Washington will seek a separate agreement that does not include Russian participation.

“I don’t see the scope for going beyond what is within the confines of the [Joint Comprehensive Plan of Action],” said the official, referring to the original 2015 nuclear deal between Iran and world powers.

“I think it’s pretty safe to say that there is no room for making exemptions beyond those,” they continued.

An accord is “within reach,” the official added, but negotiators are at an impasse due to the Russian demands, which are “the most serious stumbling block and obstacle to reaching a deal.”

“We would know within a week whether or not Russia is prepared to back down,” the official said.

If Russia does not back down, noted the official, “I do think we would be open to various alternatives. We are beginning to think about what those might be. We… at this point wouldn’t rule anything out.”

One alternative is reaching an interim deal that would curtail some of Iran’s nuclear activities in exchange for limited sanctions relief, the Journal reported.

Another, more drastic possibility is to formulate a separate agreement that would exclude Russia.