Iran's top nuclear negotiator in the ongoing Vienna talks aimed to revive the Iran nuclear deal said on Sunday that his country will not allow talks of attrition, official IRNA news agency reported.

"The exact time cannot be predicted for the duration of talks. We will not allow attritional talks. If we feel that the other parties are not serious or intending to buy time or add other issues to the discussions, we will give up the negotiations," said Abbas Araqchi, who heads the Iranian negotiating team in the ongoing talks with the representatives from the UK, China, France, Russia, and Germany in Vienna.

"At the same time, we are not in a hurry, because there are serious issues in the negotiations that need to be considered and discussed," he said.

Araqchi, who also serves as Iran's deputy foreign minister, made the remarks after a meeting with Iranian parliament's National Security and Foreign Policy Commission.

He echoed what Iran's top leader Ayatollah Ali Khamenei has said of Iran's approach to the nuclear talks: Iran will re-embrace its suspended obligations under the 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), only after the United States removes its sanctions on Iran.

The senior Iranian diplomat rejected again the "long-abandoned step-by-step plan" to revive the nuclear deal.

Iran has reduced the number of centrifuges enriching uranium to up to 60 percent purity at an above-ground plant at Natanz to one cluster from two on Thursday as reported by Reuters. 

Iran announced the shift to 60 percent, a big step towards weapons-grade from the 20 percent it had previously achieved, in response to an earlier explosion and power cut at Natanz that Tehran has blamed on Israel.

The move complicated the current indirect talks with the U.S. on rescuing its nuclear deal with major powers.

Iran gradually stopped implementing parts of its JCPOA commitments from May 2019, one year after former U.S. President Donald Trump unilaterally withdrew the U.S. from the agreement and re-imposed sanctions on Iran.

According to the 2015 nuclear agreement, Iran agreed to roll back parts of its nuclear program in exchange for decreased economic sanctions.

(With input from Xinhua)

(An Iranian national flag flutters in front of the International Atomic Energy Agency (IAEA) headquarters in Vienna, Austria, September 9, 2019. /Reuters)