(Adds further details)
THE HAGUE, March 31 (Reuters) - U.S. Afghan envoy Richard Holbrooke held a cordial and unplanned meeting with Iranian Deputy Foreign Minister Mohammed Mehdi Akhoundzadeh in The Hague on Tuesday, U.S. Secretary of State Hillary Clinton said.
Clinton told a news conference at the close of an international conference on Afghanistan: "In the course of the conference today our special representative for Afghanistan and Pakistan Richard Holbrooke had a brief and cordial exchange with the head of the Iranian delegation."
"It did not focus on anything substantive. It was cordial it was unplanned and they agreed to stay in touch."
Although the new U.S. administration has said it wants to reach out to Iran, Clinton had played down any major overtures with Iran at the Hague meeting and said beforehand she had no plans for a separate meeting with its deputy foreign minister.
"The intervention by the Iranian representative set forth some very clear ideas that we will be pursuing together," said Clinton of Akhoundzadeh’s speech.
Clinton said a U.S. government letter had been delivered to Iran during the conference asking for humanitarian help for three Americans in Iran she said were unable to return to the United States.
She named the three as Robert Levinson, a former FBI agent missing who went missing two years ago while on a business trip to Iran, and a freelance journalist, Iranian-American Roxana Saberi. The third, Esha Momeni, is an Iranian-American student detained in Iran last year.
The State Department released an excerpt of the letter: "We ask Iran to use all its facilities to determine the whereabouts and ensure the quick and safe return of Robert Levinson, and grant the release of Roxana Saberi, and permission to travel for Roxana Saberi and Esha Momeni."
"These acts would certainly constitute a humanitarian gesture by the Islamic Republic of Iran in keeping with the spirit of renewal and generosity that marks the Persian new year," said Clinton.
U.S. Senator Bill Nelson had written to Clinton last week, urging her to raise Levinson’s case with the Iranians while at The Hague. (Reporting by William Maclean, Sue Pleming and Aaron Gray-Block; editing by Mark John)