Iranian Foreign Minister Mohammad Javad Zarif said Wednesday his meeting with US counterpart John Kerry was vital for progress on talks on Tehran’s contested nuclear drive.

Iranian Foreign Minister Mohammad Javad Zarif said Wednesday his meeting with US counterpart John Kerry was vital for progress on talks on Tehran's contested nuclear drive.

"I think it's important. I think it will show the readiness of the two parties to move forward to speed up the process," he said, speaking to journalists ahead of the meeting with Kerry.

Asked if there would be a comprehensive agreement by new July 1 deadline, Zarif replied: "We'll see."

"All issues are hard until we resolve them and all issues are easy if you resolve them," he said in response to a question about  which was the greatest stumbling block.