VIENNA, TEHRAN: Iran has just days left to accept a deal on its nuclear program at talks in Vienna, France has warned. “It is not a question of weeks, it is a question of days,” French Foreign Minister Jean-Yves Le Drian told the Senate, adding that a major crisis would be unleashed if there is no agreement.

Iran’s supreme leader said on Thursday that it will further develop peaceful nuclear capacity to preserve independence.

“We will sooner or later need peaceful nuclear energy. If we do not pursue it … our independence will be harmed,” Iran’s highest authority, Ayatollah Ali Khamenei, said in a televised speech, supporting Tehran’s hard-line negotiating team in Vienna.

Ned Price, US State Department spokesperson, said the US is in “the midst of the very final stages” of indirect talks with Iran.

“This is really the decisive period during which we’ll be able to determine whether a mutual return to compliance with the JCPOA is in the offing, or if it’s not,” Price — using an abbreviation for the Joint Comprehensive Plan of Action, the 2015 deal with world powers — told reporters.

The deal lays out phases of mutual steps to bring both sides back into full compliance, and the first does not include waivers on oil sanctions, diplomats say.

Delegates say much of the text is settled but some thorny issues remain. The broad objective is to return to the original bargain of lifting sanctions against Iran, including ones that have slashed its crucial oil sales, in exchange for restrictions on its nuclear activities that extend the time it would need to produce enough enriched uranium for an atomic bomb if it chose to.

While the 2015 deal capped uranium enrichment at 3.67 percent fissile purity, Iran is now enriching to up to 60 percent, close to weapons grade.

The draft text of the agreement, which is more than 20 pages long, stipulates a sequence of steps to be implemented once it has been approved by the remaining parties to the deal, starting with a phase including Iran suspending enrichment above 5 percent purity, three diplomats familiar with negotiations said.

The text also alludes to other measures that diplomats say include unfreezing about $7 billion in Iranian funds stuck in South Korean banks under US sanctions, as well as the release of Western prisoners held in Iran, which US lead negotiator Robert Malley has suggested is a requirement for a deal.

Only once that initial wave of measures has been taken and confirmed would the main phase of sanctions-lifting begin, culminating in what many diplomats call Re-Implementation Day — a nod to the original deal’s Implementation Day, when the last nuclear and sanctions-related measures fell into place.

Iran will return to core nuclear limits like the 3.67 percent cap on enrichment purity, diplomats said.