Countries around the world condemned Iran's strikes on Israel, warning the attack could further destabilise the Middle East.
Here are some of the main reactions:
United Nations
UN Secretary-General Antonio Guterres condemned "the serious escalation".
"I am deeply alarmed about the very real danger of a devastating region wide escalation," he added, calling on parties to "avoid any action that could lead to major military confrontations on multiple fronts in the Middle East".
European Union
President of the European Commission Ursula von der Leyen called on Iran to "immediately cease" attacks, saying in a message on X, formerly Twitter, that "all actors must now refrain from further escalation and work to restore stability in the region".
Foreign policy chief Josep Borrell said the bloc "condemns in the strongest terms" the attack, calling it "an unprecedented escalation and a threat to regional security."
G7
The G7 group expressed its "full solidarity and support to Israel and its people and reaffirm our commitment towards its security", the group said in a statement following video talks.
"We demand that Iran and its proxies cease their attacks, and we stand ready to take further measures now and in response to further destabilising initiatives", it said.
NATO
NATO spokesperson Farah Dakhlallah said the military alliance condemned Iran's attack and is "monitoring developments closely", warning it is "vital that the conflict in the Middle East does not spiral out of control".
China
Beijing also urged restraint, calling the attack "the latest spillover of the Gaza conflict" and calling for the implementation of a recent UN Security Council resolution demanding a ceasefire.
"China calls on the international community, especially countries with influence, to play a constructive role for the peace and stability of the region," it added.
United States
US President Joe Biden promised "ironclad" support for Israel after holding an urgent meeting with top security officials.
"Our commitment to Israel's security against threats from Iran and its proxies is ironclad," Biden said on X, posting a picture of the meeting in the White House Situation Room.
Britain
UK Prime Minister Rishi Sunak condemned the "reckless" strikes, which he said "risk inflaming tensions and destabilising the region".
He called for "calm heads to prevail".
Canada
Canadian Prime Minister Justin Trudeau said Ottawa "unequivocally condemns Iran's airborne attacks", adding: "We stand with Israel."
Egypt
Cairo expressed "deep concern" at the escalation of hostilities and called for "maximum restraint".
The foreign ministry also warned of the "risk of the regional expansion of the conflict", and added Egypt would be "in direct contact with all parties to the conflict to try and contain the situation".
France
French President Emmanuel Macron said on X: "I condemn in the strongest terms the unprecedented attack launched by Iran against Israel, which carries the risk of destabilising the region".
Germany
German Chancellor Olaf Scholz condemned the Iranian attack as "irresponsible and unjustifiable", his spokesman said.
Foreign Minister Annalena Baerbock said the attack took the region to the "edge of a precipice".
Indonesia
Indonesia's foreign ministry said it was "deeply concerned" and called on the UN Security Council "to act immediately to de escalate tensions and continue working towards lasting peace in the Middle East, including by ending the illegal occupation of Palestine and various violations of international law by Israel".
Iraq
Iraq's President Abdel Latif Rashid called for a "reduction of tensions", warned against the "spread of conflict" and emphasised "the need to stop the aggression against the Gaza Strip and to find a solution to the Palestinian question, given this is a fundamental element to the stability of the region".
Italy
Prime Minister Giorgia Meloni condemned the attack and said she feared "destabilisation of the region".
Qatar
Qatar expressed "deep concern" following the strikes and called on "all parties to halt escalation" and "exercise maximum restraint".
The gas rich emirate, which has been engaged in weeks of talks with Israel and Hamas, urged the international community to "take urgent action to defuse the tension and de escalate."
Russia
Moscow expressed "extreme concern over the latest dangerous escalation in the region" and urged all sides to "show restraint".
"We are counting on the regional states to solve the existing problems with political and diplomatic means," the foreign ministry said.
Saudi Arabia
The Saudi foreign ministry called on "all parties to exercise utmost restraint and spare the region and its peoples from the dangers of war".
It urged the UN Security Council "to assume its responsibility towards maintaining international peace and security".
South Africa
Pretoria, which has brought a lawsuit against Israel at the top UN court over its offensive against Hamas in Gaza, said it was "gravely concerned" over possible escalation of hostilities in the region.
"South Africa has continuously stressed that irrespective of whether states believe that their use of force is lawful, it is never wise to resort to war as inevitably, it is ordinary people who bear the brunt of conflict", its foreign ministry said in a statement.
Spain
Spanish Prime Minister Pedro Sanchez called for restraint, saying Madrid "will always condemn all forms of violence which threaten the security and the well being of innocent civilians."
Syria
Syrian Foreign Minister Faisal Mekdad told his Iranian counterpart in a phone call that "Iran's response... is a legitimate right to self defence", according to state news agency SANA.
Turkey
Turkey's foreign ministry called on all sides to refrain from further escalation, saying the attack showed that "events can quickly transform into a regional war".
Ukraine
Ukraine President Volodomyr Zelensky condemned the attack, saying Iran's actions "threaten the entire region and the world, just as Russia's actions threaten a larger conflict".
"The obvious collaboration between the two regimes in spreading terror must face a resolute and united response from the world", he wrote on X.
Chile
Chile's President Gabriel Boric warned that "when tensions and crises between governments escalate into violence, it is always the people who pay."
Kenya
Kenyan President William Ruto said on X that the attack was a "disturbing development" which would "aggravate an already delicate situation in the Middle East".
"The attack represents a real and present threat to international peace and security... (and) should be condemned by all peace loving countries," he said.
Brazil
Brazil's foreign ministry said that the government was following the events with "grave concern" and called on "all parties involved to exercise maximum restraint".