The White House is calling for "the immediate release of all political prisoners in Iran," per a statement by Press Secretary Sarah Sanders.

Why it matters: Approximately 3,700 Iranian protestors were arrested in the last two weeks — a much higher number than what the Iranian government released. And the protests in Iran are the biggest since 2009; more than 25 cities have seen demonstrations and tens of thousands of Iranians are participating. While they stemmed from unrest over the economy, they quickly snowballed into something larger.

What they're saying: "The Trump Administration is deeply concerned by reports that the Iranian regime has imprisoned thousands of ‎Iranian citizens in the past week for engaging in peaceful protests. ... We will not remain silent as the Iranian dictatorship represses the basic rights of its citizens and will hold Iran’s leaders accountable for any violations. ... The United States calls for the immediate release of all political prisoners in Iran, including the victims of the most recent crackdown.

More on the backdrop of the protestors:

• President Trump has tweeted support of the protests, telling Iranians they will "see great support from the United States at the appropriate time!'
• Iran's Supreme Leader, Ayatollah Ali Khamenei, responded that Trump "seems to be a very unstable man - he must realize that these extreme and psychotic episodes won't be left without a response," Reuters reports.