Iran on Tuesday rejected Western calls to stand down its threat to retaliate against Israel for the killing of Hamas political leader Ismail Haniyeh in Tehran late last month.
The Islamic republic and its allies have blamed Israel for Haniyeh's killing on July 31 during a visit to the Iranian capital for the swearing-in of President Masoud Pezeshkian. Israel has not commented.
Iran has vowed to avenge the death, which came hours after an Israeli strike in Beirut killed a senior commander of Hezbollah, the powerful Iran-backed militant group in Lebanon.
Western diplomats have scrambled to avert a major conflagration in the Middle East, where tensions were already high due to the Israel-Hamas war in Gaza.
In a statement on Monday, the United States and its European allies urged Iran to de-escalate.
"We called on Iran to stand down its ongoing threats of a military attack against Israel and discussed the serious consequences for regional security should such an attack take place," said the joint statement from Britain, France, Germany, Italy and the United States.
The White House warned that a "significant set of attacks" by Iran and its allies was possible as soon as this week, saying Israel shared the same assessment.
The United States has deployed an aircraft carrier strike group and a guided missile submarine to the region in support of Israel.
Iran's foreign ministry spokesman Nasser Kanani criticised the Western call for it to de-escalate.
"The declaration by France, Germany and Britain, which raised no objection to the international crimes of the Zionist regime, brazenly asks Iran to take no deterrent action against a regime which has violated its sovereignty and territorial integrity," he said in a statement.
"Such a request lacks political logic, flies in the face of the principles and rules of international law, and constitutes public and practical support" for Israel.
The United States and its European allies also called for a ceasefire between Israel and Hamas in Gaza, with difficult talks set for Thursday on halting the conflict.
They also called for the "unfettered" delivery of aid to devastated Gaza.
Militants also seized 251 people, 111 of whom are still held captive in Gaza, including 39 the military says are dead.
Israel's retaliatory military offensive in Gaza has killed at least 39,897 people, according to a toll from the territory's health ministry, which does not provide a breakdown of civilian and militant deaths.
International mediators have invited Israel and Hamas to resume negotiations this week on a ceasefire and hostage release deal, an invitation Israel has accepted.
Hamas has urged mediators to implement a truce plan earlier presented by US President Joe Biden instead of holding more talks.
Analyst Esfandyar Batmanghelidj said Iran was considering how to retaliate against Israel without derailing the ceasefire talks.
"The renewed push for a ceasefire offers Iran a way out of this escalatory cycle," Batmanghelidj, CEO of the Bourse & Bazaar Foundation think-tank, told AFP.
"Iranian officials still feel obliged to hit back at Israel, but they must do so in a way that doesn't derail the prospects for a ceasefire summit."
Pressure for a ceasefire in Gaza has grown since civil defence rescuers in the Hamas-run territory said an Israeli air strike on Saturday killed 93 people at a school housing displaced Palestinians.
Israel said it targeted militants operating out of the school and mosque.
In the latest Gaza violence, Palestinian fighters clashed overnight with the Israeli army near Netzarim, south of Gaza City, an AFP correspondent reported.
Paramedics said one person was killed and others were wounded in Israeli bombing of the Al-Maghazi refugee camp in central Gaza. They were taken to Al-Aqsa Martyrs Hospital in the city of Deir el-Balah.
In the occupied West Bank, the Palestinian health ministry said Israeli forces shot dead a Palestinian man near the town of Azzun, east of Qalqilya, on Monday.
Hamas later issued a statement mourning the death of Tariq Daoud, saying he was a member of its armed wing.
A Palestinian prisoners watchdog said on Tuesday that the 18-year-old had been released on November 25 during a one-week truce that saw scores of Palestinians freed from Israeli jails in exchange for Israeli hostages held in Gaza since October 7.
