DAVOS, Switzerland - US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Jawad Zarif met here on Thursday, a senior State Department official said, the latest in an intensifying series of talks to reach a deal on Iran's disputed nuclear program. There was no immediate word on whether the two men had made progress in the hour-long session on a deal to curb Iran's nuclear work in return for an unraveling of Western economic sanctions on Tehran. Having missed a November accord for a deadline, the two sides are now looking to reach a framework agreement in March and a final long-term deal by June 30. Kerry and Zarif met as recently as last week, both in Geneva and in Paris.