A new nuclear deal with Iran is expected to be reached in "a matter of days," according to the EU's foreign policy leader.

Josep Borrell, the EU's foreign policy leader, said on Saturday that a new deal on Iran's nuclear program would most likely be reached within days.

On the margins of the Doha Forum in Qatar, Borrell told reporters, "We are extremely close, but there are still some items remaining." "I can't say when or how, but it'll be in a few days."

For weeks, international forces backing the agreement have claimed that a deal is close to being reached to revive the 2015 nuclear deal, which began to disintegrate after the United States left in 2018. 

Because of Iran's rapid nuclear program, Western parties have pushed for the discussions to be ended "immediately."

Enrique Mora, the EU negotiator's coordinator, said he was going to Tehran on Saturday in the hopes of closing gaps in the discussions.

"We're at 95%, but the remaining 5% is important," said Borrell, the EU's high representative for foreign affairs, who said that the last significant roadblock was lifted earlier this month when Russia dropped its opposition to an agreement.

"We want to stop the nuclear program from moving forward," stated Borrell. "If it doesn't happen, I'll be quite disappointed."

Concerned parties have been indicating for weeks that the talks are close to a conclusion, but that Tehran and Washington must make "political decisions."

Following the United States' unilateral withdrawal from the agreement in 2018 and the re-imposition of severe economic sanctions, Iran began to pull out of most of the accord's provisions in 2019.

The talks have been on hold since March 11, when Russia wanted assurances that sanctions imposed by the West in response to its invasion of Ukraine would not harm its commerce with Iran.

Days later, Russian Foreign Minister Sergei Lavrov said that Moscow had received the guarantees during a joint press conference with his visiting Iranian counterpart Hossein Amir-Abdollahian.

Since delegations returned to respective capitals, Amir-Abdollahian and his counterparts have continued to consult, according to IRNA.

The 2015 agreement provided Iran with much-needed sanctions relief in exchange for nuclear-related restrictions that ensured Tehran would never be able to manufacture a nuclear weapon, something it has consistently denied wanting to do.

Throughout the talks, Iran has consistently demanded assurances from the US that the 2018 departure will not be repeated.

Experts believe Iran is holding out for one of two crucial demands, the other being the removal of the Revolutionary Guards on a US terrorist blacklist.

On Tuesday, the US stated that it was now up to Iran to make difficult decisions in order to repair the agreement.

"The burden of proof is on Tehran to make difficult decisions," said State Department spokesperson Ned Price.

"There are a number of challenging challenges that we are still working to resolve."

Iran's top diplomat said on Saturday that easing US sanctions on the Islamic Revolutionary Guard Corps (IRGC) is one of Tehran's key priorities in discussions to restore the 2015 nuclear deal.

According to Reuters, Amir-Abdollahian told Iranian state television that "certainly the question of [reducing sanctions against] the Guards is part of the talks."

He further added that the IRGC has stated that a deal should not be held up over the matter, and that the Islamic Republic's "red lines" should not be crossed.

On Wednesday, Amir-Abdollahian renewed his appeal for the US to take steps to finalize the agreement.

"Amir-Abdollahian noted that while Americans pretend to be interested in resolving disputes and reaching an accord, they must also demonstrate goodwill in actuality."

He stressed that Tehran would not abandon its "red lines," which he defined as "not surrendering the interests and rights of the people."