Vienna, Oct 16 (IANS): Some progress was made in high-level negotiations on Iran's controversial nuclear programme, a US state department official said.

The official revealed this to the media after hours of meeting Wednesday between US Secretary of State John Kerry, Iranian Foreign Minister Mohammad Javad Zarif and European Union foreign policy chief Catherine Ashton in Vienna, Xinhua reported.

Iran has been negotiating with the P5 1 group -- the five permanent members of the UN Security Council plus Germany -- over the past year to find a solution to the long-standing Iran nuclear row.

A new round of talks, to be attended by negotiators from the P5 1 group and Iran, will begin Thursday in Vienna.

In the previous round of talks held in New York in September, Iran and the world's major countries failed to make significant progress, prompting some people to doubt if the negotiators could find a solution to address the remaining tough issues in the six weeks ahead of the Nov 24 deadline.

Zarif told Iranian media Tuesday that the negotiators might need more time to address the remaining concerns.

Also Tuesday, US state department spokeswoman Jennifer Psaki said the US was still exploring the possibility of reaching a comprehensive deal over Iran's nuclear programme by the deadline next month.

In November last year, relevant sides agreed on an interim deal and planned to reach a comprehensive accord July 20. Under the deal, Iran suspended sensitive nuclear activities in exchange for limited sanctions relief.

In July, Iran and the six major countries agreed to extend negotiations for four more months till Nov 24, as they were unable to narrow down significant gaps on core issues over the previous six months.

Western countries have long suspected Iran of developing nuclear bombs under the cover of Tehran's civilian nuclear programme. Iran has rejected the allegation, saying its atomic plan is exclusively peaceful.