Abdel Fattah Al-Sisi
Abdel Fattah Al-SisiReuters

An American citizen imprisoned in Egypt for the last six years died Monday after a lengthy hunger strike.

Moustafa Kassem, 54, had been arrested in 2013 as part of an Egyptian crackdown on protesters. He died of died of heart failure after imitating a liquid-only hunger strike last year to protest his conviction.

Assistant Secretary for Near Eastern Affairs David Schenker called Kassem'\s death "tragic" and "needless."

"I am deeply saddened to learn today the death of U.S. citizen Moustafa Kassem who’d been imprisoned in Egypt,” Schenker said in a State Department press briefing Monday.

"His death in custody was needless, tragic, and avoidable," Schenker added. "I’ll continue to raise our serious concerns over human rights and Americans detained in Egypt at every opportunity, as will the entire team at the Department of State."

Kassem was arrested during a sit-in which ended with security forces killing dozens of protesters. He was convicted in 2018 and sentenced to 15 years in prison.