Iran's Supreme Leader Ayatollah Ali Khamenei said in a statement read by a television presenter on Wednesday that his country will not accept US President Donald Trump's call for an unconditional surrender.

In his first remarks since Friday, when he delivered a speech broadcast on state media after Israel began bombarding Iran, Khamenei said peace or war could not be imposed on the Islamic Republic.

"Intelligent people who know Iran, the Iranian nation, and its history will never speak to this nation in threatening language because the Iranian nation will not surrender," he said.

"The Americans should know that any US military intervention will undoubtedly be accompanied by irreparable damage."

Thousands of people were fleeing Tehran on Wednesday after Israeli warplanes bombed the city overnight, and a source said Trump was considering options that include joining Israel in attacking Iranian nuclear sites.

Israel's military said 50 Israeli jets had struck around 20 targets in Tehran overnight, including sites producing raw materials, components and manufacturing systems for missiles.

Also Read: Iran shoots down advanced Israeli Hermes drone over Isfahan

A source familiar with internal discussions said Trump and his team were considering a number of options, which included joining Israel in strikes against Iranian nuclear sites.

Iran will respond firmly if US becomes involved

Iran has conveyed to Washington that it will respond firmly to the United States if it becomes directly involved in Israel's military campaign, the Iranian ambassador to the United Nations in Geneva said on Wednesday.

Ali Bahreini told reporters that he saw the US as "complicit in what Israel is doing". Iran would set a red line, and respond if the United States crosses it, he said, without specifying what actions would provoke a response.

Israel launched an air war on Friday after saying it had concluded Iran was on the verge of developing a nuclear weapon. Iran denies seeking nuclear weapons. US President Donald Trump called on Tuesday for Iran's "unconditional surrender".

Bahreini called Trump's remarks "completely unwarranted and very hostile. We cannot ignore them. We are vigilant about what Trump is saying. We will put it in our calculations and assessments."

Also Read: Israel faces shortage of Arrow Interceptors: US official says

The US has so far taken only indirect actions, including helping to shoot down missiles fired toward Israel. It is deploying more fighter aircraft to the Middle East and extending the deployment of other warplanes, three US officials said.

"I am confident that (Iran's military) will react strongly, proportionally and appropriately. We are closely following the level of involvement in the US ... We will react whenever it is needed," he said.

Thousands of people were fleeing Tehran and other major cities on Wednesday, Iranian media reported, as Iran and Israel launched new missile strikes at each other.

Iran warns of “all-out war” if US intervenes

Tensions in the Middle East escalated sharply on Wednesday as Iran warned that any United States intervention in its conflict with Israel could trigger a full-scale regional war. The warning came as both nations exchanged fire for the sixth consecutive day.

Speaking to Al Jazeera, Iran’s Foreign Ministry spokesperson Esmaeil Baghaei stated, “Any American intervention would be a recipe for an all-out war in the region.”

He emphasized: “We have very good relations with Arab countries, and they are very cognisant of the fact that Israel has been trying to drag others into the war. … We are sure our Arab countries hosting US bases would not allow their territory to be used against their Muslim neighbours,” he added.

Also Read: 10th wave of Iranian missile strikes hits targets in Israel

While US President Donald Trump initially distanced himself from the Israeli attacks, he has since hinted at a broader military campaign, saying he is aiming for something “much bigger” than a ceasefire. The US has deployed additional warplanes and is sending the USS Nimitz aircraft carrier to the region, raising fears of direct confrontation.

On Tuesday, Trump further escalated rhetoric by demanding Iran’s “unconditional surrender.”

Meanwhile, Israeli Defense Minister Israel Katz declared on X (formerly Twitter), “A storm is passing over Tehran. This is how dictatorships collapse.”

Iran-Israel military action continues

Wednesday saw intensified military action. The Israeli army reported two separate missile barrages from Iran in the early hours of the morning and said at least 10 drones were intercepted. Explosions were heard in Tel Aviv as Iran's Islamic Revolutionary Guard Corps (IRGC) claimed its advanced Fattah-1 hypersonic missiles struck targets in the commercial hub of Israel.

“The 11th wave of the proud Operation Honest Promise 3 using Fattah-1 missiles” was carried out, the IRGC said in a statement broadcast on state television.

Also Read: Trump says Khamenei is ‘easy target’; demands Tehran’s surrender

Hypersonic missiles, capable of travelling at more than five times the speed of sound and manoeuvring midflight, is difficult to detect and intercept. Iran warned Tel Aviv residents to prepare for further attacks.

IAEA confirms Karaj, Tehran uranium enrichment sites hit

In response, Israeli forces said they struck weapons manufacturing sites and a centrifuge production facility in Tehran. According to a statement on Telegram, the attacks aimed to damage Iran’s nuclear weapons development efforts. The International Atomic Energy Agency (IAEA) later confirmed that two key facilities—one in Karaj and another at the Tehran Nuclear Research Center—were hit.

Iran also claimed to have shot down an Israeli Hermes surveillance drone over Isfahan and destroyed an Israeli F-35 fighter jet in the Javadabad area of Varamin.

As the conflict rages, international concern is mounting. Governments in Russia, China, and the European Union have called for de-escalation. More than 700 foreign nationals have reportedly fled Iran into neighbouring Armenia and Azerbaijan. China’s Ministry of Foreign Affairs confirmed the evacuation of over 700 citizens from both Iran and Israel.

The US announced the temporary closure of its embassy in Jerusalem due to security concerns.

According to a Washington-based Iranian human rights organization, at least 585 people have been killed in the conflict so far, including 239 civilians. Over 1,300 people have been wounded in Israeli strikes on Iran. Iranian attacks on Israel have reportedly resulted in at least 24 deaths.