United Nations Secretary General Antonio Guterres warned the international community Sunday against deeper descent into conflict, addressing the Security Council during a meeting over Iran's weekend attack on Israel.

"Neither the region nor the world can afford more war," Guterres said.

"The Middle East is on the brink," he told the Security Council.

"The people of the region are confronting a real danger of a devastating full-scale conflict. Now is the time to defuse and de-escalate," he added, calling for "maximum restraint."

Late on Saturday, Iran launched a direct attack on its long-time arch foe Israel for the first time, firing a wave of more than 300 missiles and drones.

Nearly all of them were intercepted by Israel and others, including the United States, Jordan and Britain.

According to the Israeli army, 12 people were injured.

Iran said its attack came in response to a deadly April 1 air strike on Tehran's consulate building in the Syrian capital Damascus that was widely blamed on Israel.

That attack killed seven Iranian Revolutionary Guards, including two senior generals, and prompted Iranian threats of retaliation.

The unprecedented exchange, marking a major escalation between the two countries, has sparked renewed fears of a broader conflict, including the potential for an Israel counterstrike.

'Step back from the brink'

The United States said Sunday it will not join any Israeli counterattack on Iran, with President Joe Biden warning Prime Minister Benjamin Netanyahu to "think carefully" about any escalation.

The rising tensions come against the backdrop of Israel's six-month-old war against Hamas in Gaza, which began after the Palestinian Hamas group's unprecedented attack in Israel October 7 which resulted in the deaths of 1,170 people, mostly civilians, according to a tally based on Israeli figures.

Israel's retaliatory offensive has killed at least 33,729 people in Gaza, mostly women and children, according to the territory's Hamas-run health ministry.

Since the start of the conflict, Iran-backed groups in Iraq, Lebanon, Syria, and Yemen have carried out a flurry of attacks on Israeli and Western targets.

Sunday's Security Council session on the simmering crisis came at Israel's request, with its Ambassador Gilad Erdan urging the council to "take action (and) condemn Iran for their terror."

The body must "impose all possible sanctions on Iran before it's too late," he said.

Iran's UN envoy Amir Saeid Iravani meanwhile insisted the Islamic republic was exercising its "inherent right to self-defense."

"The Security Council... failed in its duty to maintain international peace and security," Iravani said.

Therefore, Tehran "had no choice" but to respond, he said, adding that his country does "not seek escalation or war," but will respond to any "threat or aggression."

During his speech, Guterres repeated his condemnation of Iran's strikes on Israel, and the Israeli attack on the Iranian consulate in Damascus.

"It's time to step back from the brink. It is vital to avoid any action that could lead to major military confrontations on multiple fronts in the Middle East," Guterres said.

He also repeated his call for an "immediate humanitarian ceasefire" in Gaza, which experts warn is on the verge of famine.