The US believes that the P5+1 nuclear talks with Iran can reach a comprehensive plan of action by June 30.

"These are complicated talks and there are complicated issues that we have to work through at this stage… it is still our belief that we can reach conclusion of the talks by the deadline," Director of the Press Office at the US State Department Jeff Rathke said in a press briefing.

"We’ve always made clear to the Iranians that they will have to reach agreement with the IAEA on providing the necessary access to address the concerns about the possible military dimensions of their program; and without that agreement, we will not be able to move forward with sanctions relief. That’s been our position throughout these negotiations," he said.