On Tuesday, the Algerian parliament appointed Bensaleh interim leader in accordance with Article 102 of the country's constitution.
According to the constitution, the parliament speaker will hold the position for a 90-day period, during which presidential elections will be held.
Many opposition parties, however, reject Bensaleh's appointment due to his longstanding affiliation with the Bouteflika regime.
"This responsibility has been imposed on me as a constitutional duty," Bensaleh said in a speech following his appointment.
He went on to vow to "give back to the Algerian people the ability to choose their own leaders".
Algeria has had five interim presidents since it won its independence in 1962. Past interim presidents were generally appointed to lead transitional periods or to overcome internal crises.
Bensaleh, 78, had long been considered a pillar of the Bouteflika regime. He assumed the parliamentary speakership in 1997, two years before Bouteflika assumed the presidency.
He began his career as a journalist in the mid-1960s before becoming the director of state-run newspaper Al-Shaab. He also worked as a correspondent for Algeria's Al-Mujahid and Al-Gomhuriya newspapers.
Bensaleh entered political life in 1977 when he was elected MP for the northwestern state of Tlemcen – a post he would hold for three consecutive terms.
He left his parliamentary post in 1989 when he was appointed ambassador to Saudi Arabia. In 1993, he became foreign minister.
Bensaleh returned to parliament after heading Algeria's Transitional Council in the 1990s before founding a new political party, the National Democratic Rally (RND), with several other politicians.
In 2001, a dispute erupted between Bouteflika and then-Assembly Speaker Bashir Boumaza, which led to the latter's replacement by Bensaleh in 2002.
Since then, Bensaleh has been seen as Bouteflika's "number two".
After Bouteflika suffered a stroke in 2013, Bensaleh became the ageing leader's personal representative at regional and international forums, particularly at Arab League sessions.
Bensaleh later became known for his speeches praising Bouteflika's achievements and attacking the president's opponents.