The Obama administration said Wednesday it has rescinded invitations to Iranian diplomats to attend July 4 U.S. Independence Day celebrations at American diplomatic missions around the world. The State Department said an Iranian presence at such events would be incongruous with a celebration of American values.

The Obama administration says it is not closing the door to eventual dialogue with Iran on such issues as its support of terrorism and nuclear program.

But in a symbolic protest of what the State Department Wednesday termed Iran's appalling and deplorable treatment of election protestors, it is withdrawing invitations for Iranian diplomats to attend traditional U.S. embassy Fourth of July parties.

The two countries have not had formal relations since Iran's 1979 Islamic revolution and interaction between the two countries' diplomats has been infrequent.

The Obama administration came into office offering outreach to Tehran, including a direct U.S. role in big-power contacts with Iran on its nuclear program.

Secretary of State Hillary Clinton three weeks ago authorized U.S. diplomatic missions to invite Iranians to the July 4th observances, which typically include outdoor hot dog roasts and American music, as a goodwill gesture.

White House Press Secretary Robert Gibbs said Wednesday no Iranians have responded to the invitations thus far, and that in any event they are no longer valid.

Earlier at a news briefing here, State Department Spokesman Ian Kelly said the embassy events celebrate American values such as freedom and independence, precisely what Iranians have taken to the streets to demand. As such, Kelly said, an official Iranian presence would be inappropriate.

"Given everything that's going on, given the kind of response that the Iranian government has had to the desires of the Iranian people to have their voices be heard, to have their basic freedoms be respected - these are the most fundamental American political values that we have," said Ian Kelly. "I think it would be incongruous for Iranians to want to go to a celebration like that."

The Iranian government also did not reply to an Italian invitation to participate in talks on the sidelines of the G-8 foreign ministers meeting later this week in Trieste.

It has similarly failed to respond to an invitation by European Union Foreign Policy chief Javier Solana for a new round of talks on its nuclear program with the five permanent U.N. Security Council member countries and Germany, the P5+1.

The P5+1 last year presented Iran with a revised offer of incentives for it to halt a uranium enrichment effort U.S. and European officials believe is weapons-related and return to negotiations on its nuclear program.

Secretary of State Hillary Clinton was to have attended the G-8 ministerial, and a weekend meeting of OSCE foreign ministers in Greece, but had to cancel because of her recent surgery for a broken elbow.

But spokesman Kelly said Clinton remains engaged in telephone diplomacy on Iran, discussing the election violence Wednesday with Russian Foreign Minister Sergei Lavrov and Chinese Foreign Minister Yang Jiechi. They also discussed the North Korean nuclear program.

In a related development, a State Department official confirmed Wednesday that in early May, before Iran's disputed June 12 election, President Obama sent a letter to Iranian supreme leader Ayatollah Ali Khamenei reiterating U.S. interest in improved relations.

The State Department however declined to discuss specific contents of the letter, which the Iranian religious leader referred to in a sermon last Friday accusing the United States of helping promote protests in his country.

At his news conference Tuesday, President Obama again denied any such activity.