WASHINGTON  The Obama administration says it has tried to avoid words or deeds that could be portrayed as American meddling in Iran’s presidential election and its tumultuous aftermath.

Yet on Monday afternoon, a 27-year-old State Department official, Jared Cohen, e-mailed the social-networking site Twitter with an unusual request: delay scheduled maintenance of its global network, which would have cut off service while Iranians were using Twitter to swap information and inform the outside world about the mushrooming protests around Tehran.

The request, made to a Twitter co-founder, Jack Dorsey, is yet another new-media milestone: the recognition by the United States government that an Internet blogging service that did not exist four years ago has the potential to change history in an ancient Islamic country.

“This was just a call to say: ‘It appears Twitter is playing an important role at a crucial time in Iran. Could you keep it going?’ ” said P.J. Crowley, the assistant secretary of state for public affairs.