US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif will meet here Thursday for talks that analysts say could pave the way for warmer US-Iranian relations after a decades-long freeze. The White House announced that Kerry and Zarif would both attend the P5+1 international talks over the future of Iran’s nuclear program on the sidelines of the UN General Assembly. Thursday’s encounter between Kerry and Zarif will be the highest-level substantive meeting since the countries severed diplomatic ties following Iran’s Islamic revolution in 1979. \"We welcome Iran engaging seriously through that process given that it represents the international community\'s commitment to holding Iran accountable, but also being open to a diplomatic resolution,\" Deputy National Security Adviser Ben Rhodes said. The meeting was initially announced by Catherine Ashton, the European Union foreign policy chief. Ashton made the announcement after meeting, for the first time, with Zarif on the eve of the UN General Assembly in New York. \"What I saw today is energy and determination to move forward on our talks and many things flow from that,\" said Ashton, who will convene the group. She added that diplomats and experts from the negotiating group would meet then with an Iranian team next month in Geneva to talk about the details of a possible nuclear compromise. Shortly after the White House confirmed the meeting, US State Department spokeswoman Jen Psaki issued a statement reaffirming the United States\' readiness \"to work with Iran,\" provided the administration of newly sworn-in Iranian President Hassan Rouhani will \"choose to engage seriously.\" Rouhani and President Barack Obama are also in New York City this week for the annual high-level meetings of the UN General Assembly. But there are currently no plans for the two leaders to meet face to face, Deputy National Security Adviser Ben Rhodes told reporters Monday.