The Islamic Jihad terrorist group selected a new leader for the first time in more than 20 years Thursday, but is likely to remain close to Iran, said a senior official quoted by AFP.

Syria-based Ziad al-Nakhala will take over as the movement's secretary general from Ramadan Shalah, who has been suffering from serious health issues for months, the official said on condition of anonymity.

Shalah, who has led the organization since 1995, is believed to be in a coma after an unknown illness, though the group has not publicly confirmed this.

The official said Nakhala was selected without a challenger, with a second source in the party confirming the announcement.

Nakhala, who was born in Gaza in 1953, is close to both Iran as well as its Lebanese proxy Hezbollah.

He had been the deputy leader to Shalah since the 1990s.

Islamic Jihad is heavily backed by Iran. Two years ago, the Islamic Republic pledged to provide $70 million in annual assistance to terror group's "jihad" against the State of Israel.

The move was seen as a serious snub by Iran towards Hamas, Islamic Jihad's main rivals in Gaza.

Once a key Iranian proxy, Hamas fell out of favor with the Islamic Republic after refusing to openly back the Assad regime at the outbreak of the Syrian civil war in 2011. Years of stuttering relations from then deteriorated completely after a senior Hamas delegation visited Saudi Arabia in 2015, in what Tehran perceived as a slap in the face.

In recent years, however, Iran and Hamas have resumed their close relationship.

The Islamic Jihad is considered a terrorist organization by the United States and the European Union, and the US labelled Nakhala himself a "global terrorist" in 2014.