WASHINGTON — An American prisoner’s hunger strike in Iran has renewed pressure on the Biden administration to cut a deal with Tehran that would free several US citizens held in Iranian custody.

Siamak Namazi, currently the longest-held American prisoner in Iran, embarked Monday on a seven-day hunger strike — one day to mark each year he’s spent behind bars. Namazi is detained in the notorious Evin Prison, where his family says he has endured long stretches of solitary confinement and torture. 

Namazi, a businessman arrested in 2015 and handed a 10-year prison sentence for “colluding with foreign countries,” was the only American not returned home as part of a January 2016 prisoner exchange under the Obama administration that occurred the same day the Iranian nuclear deal took effect. Namazi was also left out of two subsequent prisoner releases negotiated by the Trump administration. 

The Biden administration says bringing wrongfully detained US citizens home from Iran is a top priority. In a letter he penned from prison, Namazi called for President Joe Biden to make good on that pledge, including by meeting with the families of the imprisoned Americans.