U.S. Secretary of State John Kerry on Tuesday welcomed the U.N. nuclear watchdog's decision to close its investigation into whether Iran once had a secret nuclear weapons program.

In a written statement released in Moscow, where he is holding talks with top Russian officials on the Syrian civil war, Kerry also said the decision by the International Atomic Energy Agency's (IAEA) board would allow it to focus on the implementation of a July 14 deal under which Iran agreed to curb its nuclear program in return for sanctions relief.

In a symbolic victory for Iran, the IAEA Board of Governors passed a resolution ending its long-running inquiry but allowing inspectors to continue to police the country's nuclear program.

"Closing the (Possible Military Dimensions) agenda item will in no way preclude the IAEA from investigating if there is reason to believe Iran is pursuing any covert nuclear activities in the future, as it had in the past," Kerry said, saying the July 14 deal, called the Joint Comprehensive Plan of Action (JCPOA), improved the agency's ability to monitor Iran.

"Today�s resolution makes clear that the IAEA�s Board of Governors will be watching closely to verify that Iran fully implements its commitments under the JCPOA," he said. "We will remain intensely focused going forward on the full implementation of the JCPOA in order to ensure the exclusively peaceful nature of Iran�s nuclear program."

By Reuters