Every country in G5+1 sometimes have different interest, position and policy but we negotiate with G5+1in general, Zarif said.

Iranian Foreign Minister Mohammad Javad Zarif and his US counterpart John Kerry started a second round of talks Wednesday in an attempt to find solutions to the sticking points in the way of striking a deal between Iran and P5+1.

Iranian deputy foreign ministers, Abbas Araqchi and Majid Takht-e Ravanchi, as well as US Undersecretary of State for Political Affairs Wendy Sherman are also present in the meeting.

Meanwhile last night, U.S. negotiators announce will continue talks with Iran until at least Thursday morning.

Also German Foreign Minister Frank-Walter Steinmeier has cancelled a planned trip Thursday to the Baltics in order to stay at nuclear talks between Iran and world powers, a German diplomat said.

"Foreign Minister Steinmeier will not make his planned visit to the... Baltic countries in view of the ongoing talks on the Iranian nuclear programme here in Lausanne," the source said as negotiators took a break after working through the night.

US Secretary of John Kerry and his Iranian counterpart huddled all night until early dawn Thursday negotiating face-to-face as they sought to clinch a hard-fought deal to curtail Iran's nuclear programme.

They were joined by the EU's deputy foreign policy chief Helga Schmid for the marathon session, aiming to end a stalemate which has dragged the negotiations beyond a March 31 deadline.

"We are a few metres... from the finishing line, but we are well aware that the final metres are the hardest," French Foreign Minister Laurent Fabius told reporters, as he arrived back in Switzerland to rejoin the negotiations.

Diplomats and experts from Britain, China, France, Germany, Russia and the United States also remained hard at work all night with their Iranian counterparts in a luxury Lausanne hotel in a flurry of separate meetings, before finally breaking from the negotiations just before dawn.