Faraji Rad maintained that the impasse in the Vienna talks will be broken.
He said the 2015 nuclear deal, JCPOA, is on track to be revived unless the negotiations run into an unexpected problem.
Faraji Rad said the situation has improved and no key issues remain to be resolved.
The former Iranian ambassador to Norway said Iran and the P4+1 group have taken positive steps to resolve their differences.
Faraji Rad said the P4+1 and the US want to put an end to the safeguards issue so that a deal will be reached.
He noted that the Western governments want the International Atomic Energy Agency to close the case of the three sites in which they claim Iran performed undeclared nuclear activities.
The former diplomat said Iran and the US will however haggle over a final deal to the end so they can get as many concessions as they can. He said Iran and the West must be careful so that Russia will not hamper the potential agreement in Vienna.
Faraji Rad said both Iran and the US need the JCPOA to be revived, adding the Iranians want to solve their economic problems after the sanctions are removed and the US and the Europeans want to resolve their energy problems.
Faraji Rad stressed that even the Chinese need the deal to be restored so that they can have better economic ties with Iran.