Iran has rejected American and Arab efforts to tone down its response to the Israeli assassination of Hamas Political Bureau chief Ismail Haniyeh in Tehran, The Wall Street Journal reported on Sunday.

On July 31, the IRGC announced the martyrdom of Haniyeh, who was on a visit to Tehran to attend the inauguration ceremony of Iran's new President Masoud Pezeshkian.

The WSJ cited people familiar with the talks as saying that Tehran informed Arab diplomats on Saturday that it is unconcerned if its response to the Israeli assassination leads to the outbreak of war.

According to the sources, the United States requested Europe and other allied governments to convey a message to Iran urging it to avoid escalation, warning that any major strike could provoke a response.

Washington also hinted that efforts by Iran’s new President Masoud Pezeshkian to enhance engagement with the West would stand a better chance if Tehran demonstrated restraint.

As part of its message to Iran, the US also claimed that it was urging "Israel" to de-escalate as well.

The Wall Street Journal pointed out that "Iran has refused to provide detailed warnings that would help mitigate the impact of any strike."

Earlier, Al Mayadeen's correspondent in Tehran cited an informed Iranian source as saying that Iran considers Haniyeh's assassination to be one of its red lines that was crossed, "regardless of the details of the operation," indicating that it will handle the response accordingly.

That is why "Iran will respond in a way that crosses the red lines set by the Israeli occupation," the informed source affirmed.

They also pointed out that "Iran will not yield to pressures and messages of de-escalation because any abandonment of retaliation will open the door to more Israeli aggressions."

Iran vows stronger response than 'Operation True Promise': Exclusive

Kazem Gharibabadi, the Deputy Chief for International Affairs of the Iranian Judiciary, warned in an interview for Al Mayadeen that the Israeli occupation would face severe repercussions for its actions, such that "it would not dare to commit further acts of terrorism or violate Iran’s sovereignty."

He emphasized that the response to Haniyeh's assassination would be "more decisive than Operation True Promise," referring to Iran's April 13 retaliation to the Israeli aggression that targeted the Iranian consulate in the Syrian capital Damascus on April 1.

Gharibabadi described the Israeli action as "an act of terrorism that defies international resolutions," arguing that it reveals not the strength but the impotence of the Israeli entity.

He asserted that the killing of innocent civilians, including women and children in Gaza, demonstrates the defeat of the Israeli entity.

In the same vein, the Speaker of the Iranian Parliament, Mohammad Bagher Ghalibaf, affirmed Sunday that his country "has not and will not leave any attack on its sovereignty unanswered," stressing that the Israeli occupation and the United States "will regret their actions and will be forced to change their calculations."

Read more: Source tells Tasnim NYT report on Haniyeh assassination false