The United States is joining calls for the release of two Iranian opposition leaders who were put under house arrest two years ago.
The State Department noted Mir Hossein Musavi and Mehdi Karrubi have not been charged with any crimes since being detained in 2011.
Musavi's wife, Zahra Rahnavard, a women's rights activist, is also under house arrest.
Musavi and Karrubi ran in Iran's 2009 presidential election.
President Mahmud Ahmadinejad was declared the winner of the election amid opposition claims the vote was rigged, sparking street protests.
The State Department also expressed concern over the ongoing bans on political parties and imprisonment of political leaders ahead of Iran's presidential elections in June.
The State Department statement comes after the EU also called for the immediate release of Musavi and Karrubi.