The United States warned Iran at the United Nations Security Council on Wednesday against targeting it or Israel as UN Secretary-General Antonio Guterres said the "deadly cycle of tit-for-tat violence must stop" in the Middle East.
"Time is running out," he told the council.
The 15-member council met after Israel killed the leader of Lebanon's Hezbollah and began a ground assault against the Iran-backed armed group and Iran attacked Israel in a strike that raised fears of a wider war in the Middle East.
"Our actions have been defensive in nature," US Ambassador to the UN Linda Thomas-Greenfield told the council.
"Let me be clear: The Iranian regime will be held responsible for its actions. And we strongly warn against Iran – or its proxies – taking actions against the United States, or further actions against Israel," she said.
French UN Ambassador Nicolas de Riviere said France wants the Security Council to "show unity and to speak with one voice" to de-escalate the situation. Thomas-Greenfield said the council should condemn Iran's attack and impose "serious consequences" on Iran's elite Revolutionary Guards Corps for its actions.
"We have a collective responsibility, as members of the Security Council, to impose additional sanctions on the IRGC for supporting terrorism, and for flouting so many of this Council's resolutions," the US ambassador said.
Guterres told the council he strongly condemned Iran's attack on Israel. Earlier on Wednesday, Israel's foreign minister said he was barring Guterres from entering the country because he had not done so.
Russia's UN Ambassador Vassily Nebenzia praised Iran for "exceptional" restraint in recent months and said the missile attack on Israel could not be "presented as though all of this happened in a vacuum, as though nothing is happening - and nothing did happen - in Lebanon and Gaza, in Syria, in Yemen."
"But it did happen, and it led to a new, very dangerous spiral of a widening Middle East conflict," Nebenzia said.
In a letter to the Security Council on Tuesday, Iran justified its attack on Israel as self-defense under Article 51 of the founding UN Charter, citing "aggressive actions" by Israel including violations of Iran's sovereignty.
"Iran ... in full compliance with the principle of distinction under international humanitarian law, has only targeted the regime's military and security installations with its defensive missile strikes," Iran wrote to the council.
Israel's UN Ambassador Danny Danon on Wednesday rejected Iran's claim of self-defense.
"It was a calculated attack on a civilian population," he told reporters before the council met. "Israel will not stand by in the face of such aggression. Israel will respond. Our response will be decisive, and yes, it will be painful, but unlike Iran we will act in full accordance with international law."