Israel will pay a 'heavy price', Iran's former nuclear negotiator

Analysts and Hamas officials have told Reuters that Haniyeh's most likely successor is Khaled Meshaal, his deputy-in-exile who lives in Qatar.

Mashal headed Hamas politburo until 2017. He was widely recognized as the organizations top man for more than a decade, following the assassination of Hamas leader Abdel Aziz al-Rantisi in 2004.

Mashal narrowly survived an attempt on his life in Jordan ordered by Netanyahu in 1997.

Analysts say Mashal's relationship with Iran's leaders was not as warm as that of Haniyeh, although he had also travelled to Tehran on several occasions.

Iran's ambassador to the UN has asked the Security Council to convene an emergency meeting to address “Israeli aggression and terrorist attacks”.

Hamas leader Ismail Haniyeh was killed in Tehran early hours of Wednesday local time. The assassination, Amir Saeid Iravani wrote in a letter Wednesday, "suggests an intention to escalate conflict and expand the war through the entire region."

He urged the international community to take “decisive action" to "hold the perpetrators accountable.”

Iranian journalist and political analyst, Jamshid Barzegar, told Iran International that publicizing Haniyeh's trip to Tehran in real time may have helped those who wanted to target him.

"After the October 7 attack, Haniyeh traveled to Tehran several times. In all those previous trips, news of his presence in Tehran and his meetings were published a few days after his trip had ended. The release of this news, contrary to the previous practice, made things somewhat easier for Israel."

He added that Israel's "intelligence oversight" over the leaders of Hamas, Hezbollah, and even Iran is "undeniable".

Responding to questions about the assassination of Hamas leader in Tehran, EU external affairs spokesperson Peter Stano said, "the EU has a principled position of rejecting extrajudicial killings and of supporting the rule of law, including in international criminal justice."

He also said that ICC was seeking an arrest warrant against Ismail Haniyeh on charges of war crimes.

The EU has listed Hamas as a terrorist organization.

Stano said the EU is "closely" following the situation in the Middle East, urging "all parties" to avoid escalation.

Without directly naming the parties involved, the UAE expressed deep concern over the escalating tensions in the region.

The UAE's foreign ministry stated that it is "closely monitoring the rapid regional developments" and is worried about the impacts on security and stability.

The statement emphasizes that "enhancing dialogue, adhering to international laws, and respecting the sovereignty of states are the best foundations for resolving current crises."

The UAE calls for resolving disputes through diplomatic means, advocating for an approach that avoids confrontation and escalation.