THE HAGUE — It was brief, it was spontaneous, and it was not substantive, but a meeting Tuesday between Richard C. Holbrooke, a presidential envoy, and an Iranian diplomat was the first public face-to-face encounter between the Obama administration and the government of Iran.
Secretary of State Hillary Rodham Clinton confirmed that Mr. Holbrooke, the special representative for Afghanistan and Pakistan, met with Iran’s deputy foreign minister, Mohammad Mehdi Akhondzadeh, on the sidelines of a conference devoted to Afghanistan.
“It was cordial, unplanned, and they agreed to stay in touch,” Mrs. Clinton said to reporters at the end of the conference. “I myself did not have any direct contact with the Iranian delegation.”
Mrs. Clinton also said the United States handed the Iranian delegation a letter asking for its help in the cases of two American citizens who are being held in Iran and another who is missing.
The two American contacts with Iran, however modest, mark a step forward in the Obama administration’s policy of reaching out to the Iranian regime. Mrs. Clinton also spoke positively of remarks delivered by Mr. Akhondzadeh about what Iran would do to help stabilize Afghanistan and to cooperate in regional efforts to crack down on the booming Afghan drug trade, which has spilled over its border.
“The fact that they came today, that they intervened today, is a promising sign that there will be future cooperation,” she said.
“The questions of border security, and in particular the transit of narcotics across the border from Afghanistan to Iran is a worry that the Iranians have, which we share.”
The unsigned letter, which an American official handed directly to the Iranian delegation, keeps up American pressure on Tehran in three troublesome human-rights cases.
“We ask Iran to use its facilities to determine the whereabouts and insure the quick and safe return of Robert Levinson, and the grant the release of Roxana Saberi, and permission to travel for Roxana Saberi and Esha Momeni,” Mrs. Clinton said, quoting the letter. “These acts would certainly constitute a humanitarian gesture by the Islamic Republic of Iran.”
Mr. Levinson, a former F.B.I. agent, disappeared in March 2007, reportedly while investigating a cigarette smuggling case on Kish Island, off Iran. Ms. Saberi, a freelance journalist who has worked for National Public Radio, was arrested by Iranian authorities on Jan. 31 after buying a bottle of wine.
Ms. Momemi, a graduate student at California State University, Northridge, was arrested last October, allegedly for a traffic violation. She was conducting research on the Iranian women’s movement.
Mrs. Clinton explained the Obama administration’s decision to deploy 17,000 additional soldiers, as well as 4,000 more military trainers to help build up Afghan security forces. Afterward, the Iranian government said sending more foreign troops to Afghanistan would be ineffective, arguing that the “the presence of foreign forces has not improved things in the country.”
The United States and Iran sat across a horseshoe-shaped conference table here, at which more than 80 countries and international organizations assembled to discuss policy toward Afghanistan.