WASHINGTON, USA: The U.S. State Department said on Tuesday it had contacted the social networking service Twitter to urge it to delay a planned upgrade that would have cut daytime service to Iranians who are disputing their election.

Confirmation that the U.S. government had contacted Twitter came as the Obama administration sought to avoid suggestions it was meddling in Iran's internal affairs as the Islamic Republic battled to control deadly street protests over the election result.

Twitter and Facebook have been used as a tool by many young people to coordinate protests over the election's outcome.

President Barack Obama said earlier on Tuesday he believed "people's voices should be heard and not suppressed" in Iran.

Obama, who has sought direct engagement with Iran, also said he did not want to be seen as "meddling" in Iranian internal affairs, given the two countries' rocky history.

But his spokesman Robert Gibbs said Obama has "deplored and condemned the violence that we've seen, and underscored that the world is seeing in Iran a yearning for change."

Twitter Inc said in a blog post it delayed a planned upgrade because of its role as an "important communication tool in Iran." The hourlong maintenance was put back to 5 p.m. EDT/2100 GMT, which corresponds to 1:30 a.m. on Wednesday in Iran.

The upgrade originally had been planned for Monday night in the United States, which would have cut daytime service in Iran on Tuesday.

The State Department declined to give immediate details of the contact with Twitter, which has been used particularly by young urban Iranians who are disputing President Mahmoud Ahmadinejad's re-election last Friday.

"We highlighted to them that this was an important form of communication," said a State Department official of the conversation the department had with Twitter officials.

Any sign of U.S. involvement in the actions of Twitter or any other social networking service could be seized on by Iran as U.S. interference in the electoral process.

Iranian officials declared that Ahmadinejad defeated his more moderate challenger, former prime minister Mirhossein Mousavi, in last Friday's election, triggering massive street protests by Iranians questioning the election's legitimacy.

State Department spokesman Ian Kelly strongly rejected that contacts to Twitter amounted to meddling in Iranian internal affairs.

"This is about giving their voices a chance to be heard. One of the ways that their voices are heard are through new media," Kelly told reporters.

He said there were contacts with Twitter over the weekend.