Vienna, July 7 (IANS): European Union foreign policy chief Federica Mogherini said on Tuesday that the talks between representatives of Iran and the six major world powers over Tehran's nuclear programme will continue for at least two more days, IRNA news agency reported.

"We are continuing the negotiation... Some ministers are leaving, but will be back in the coming hours or days," she said, adding that the talks would go beyond the July 7 deadline but it did not mean extension.

She noted that the departure and comeback of ministers was something normal and did not mean evaluation of the talks.

The EU foreign policy chief said the talks between the P5 1 group of world powers -- the US, Britain, France, Russia, China, plus Germany -- and Iran were at the toughest stage and dealing with the most difficult issues.

"We are continuing to negotiate for the next couple of days... We entered the most difficult and sensitive part of the talks," Mogherini said.

She said the two sides still believed that an agreement was available, even as she acknowledged that the current stage of the talks would be hard and challenging.

Mogherini said the negotiators were flexible about the deadline and they shouldered an important responsibility.

She said that the negotiating teams have accomplished composing the context of the deal. "The window of opportunity should be kept open. The time for agreement is exactly now," the EU foreign policy chief said.