President Obama exchanged a handshake with Iran's top diplomat at the United Nations, a U.S. official said Tuesday, in a small but closely watched gesture as the two countries move ahead with a nuclear accord.

Iran's foreign minister, Mohammad Javad Zarif, is well known to Secretary of State John Kerry and other U.S. envoys following the long negotiations over the accord that limits Iran's nuclear program in exchange for easing of international sanctions.

But the handshake broke new ground: It was the first between a U.S. president and Iran's foreign minister since the 1979 Islamic revolution and the hostage-taking at the U.S. Embassy in Tehran that followed.

A senior Obama administration official said the president and Zarif shook hands during a brief exchange at a lunch.

Washington Post