Many young Iranians have been using Twitter to discuss the disputed poll
The US state department has revealed it asked social networking site Twitter to delay planned maintenance work to allow Iranians communicate with each other.
Twitter administrators were contacted over the weekend and urged to refrain from taking the site offline on Monday, a state department official said.
The planned upgrade work could have cut daytime services for Iranians.
Iran has restricted access to websites like Facebook and blocked SMS messages after a disputed presidential election.
The move by Tehran is seen as an attempt to disrupt mass protest rallies after Friday's poll, which the opposition claims was rigged in favour of President Mahmoud Ahmadinejad.
There is no indication that the US administration is using Twitter to communicate with Iranians, and Washington has been careful not to appear to be meddling, the BBC's state department correspondent Kim Ghattas says.
But she adds that with no direct ties between Tehran and Washington and no US embassy in Iran, it appears that US officials are also relying on social networking websites to obtain information about developments inside Iran.