BEIJING - US President Donald Trump will decide on whether he will order a strike against Iran in the next two weeks, as aerial conflict between Israel and Iran continues one week after a surprise attack by Israel.

"Based on the fact that there's a substantial chance of negotiation that may or may not take place with Iran in the near future, I will make my decision whether or not to go in the next two weeks," White House Press Secretary Karoline Leavitt said at a briefing on Thursday.

Iran must agree to no enrichment of uranium, and Tehran must not be able to achieve a nuclear weapon as part of any diplomatic agreement, Leavitt read a statement from Trump.

Correspondence between the United States and Iran "has continued" as the two sides engage in negotiations, Leavitt said, echoing Thursday reports that US special envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi have talked by phone several times since Israel began its strikes on Iran on June 13, in a bid to find a diplomatic end to the crisis.

Araghchi told Witkoff that Tehran "could show flexibility in the nuclear issue" if the US government pressured Israel to end the war, adding Tehran would not return to negotiations unless Israel stopped the attacks, local media quoted a regional diplomat.

Trump approved attack plans on Iran Tuesday night, but held off making a final decision in case Iran agrees to abandon its nuclear program, media reported.

Iran's Supreme Leader Ali Khamenei said Wednesday that the country remains steadfast amid its conflict with Israel and will not surrender to anyone amid pressure, warning that any American military intervention would cause "irreparable damage".

Since June 13, Israel has launched large-scale airstrikes on multiple locations in Iran, targeting nuclear facilities and military sites, resulting in heavy casualties. In retaliation, Iran carried out multiple rounds of missile and drone attacks on various targets inside Israel.

The aerial conflict has yet shown no sign of easing as it drags into a second week.

On Thursday, Israel and Iran exchanged major airstrikes overnight, targeting each other's critical infrastructure and military facilities.

The Israel Defense Forces announced in a statement on Thursday that it had launched a broad aerial campaign across Iran, including strikes targeting the inactive Arak nuclear reactor in western Iran, and a nuclear weapons development site in Natanz, central Iran.

In addition to nuclear-related targets, Israeli warplanes reportedly struck a range of military production sites across Iran, including factories manufacturing ballistic missile components, facilities assembling Iranian air defense systems and various logistical infrastructures, the statement said.

In response to the Israeli offensive, Iran targeted Israel's military intelligence facilities in its strikes on the southern part of the country on Thursday morning, not a hospital as was reported by some media outlets, Iran's state news agency IRNA said.

The strikes were aimed at the Israeli army's C4I telecommunications corps headquarters and an intelligence facility, IRNA said, adding that the hospital in question was affected by the blast's shockwave.

Also on Thursday, Iran's Islamic Revolution Guards Corps appointed Majid Khademi as the new head of its intelligence organization, days after Mohammad Kazemi, the organization's former chief, and his deputy Hassan Mohaghegh were killed in Israeli airstrikes on Tehran on Sunday, the semi-official Fars News Agency reported.

Besides top military commanders, Israeli strikes have killed a number of nuclear scientists and hundreds of civilians in Iran.

Arash, 33, a government employee in Tehran, was quoted by Reuters as saying that a building next to his home in Tehran's Shahrak-e Gharb neighborhood had been destroyed in the strikes.

"I saw at least three dead children and two women in that building. Is this how Netanyahu plans to 'liberate' Iranians? Stay away from our country," he said.

The United Nations High Commissioner for Human Rights Volker Turk said in a statement on Thursday the large-scale attacks have caused serious human rights and humanitarian impacts on civilians and risk igniting a broader regional conflict.

Turk noted that the intense airstrikes and missile and drone attacks have gone far beyond military targets, resulting in significant civilian casualties and widespread damage to civilian infrastructure.

According to official figures, nearly 600 people have been killed in Iran and 24 in Israel since fighting began.

The UN official urged all parties to exercise maximum restraint, fully respect international law, and return in good faith to the negotiating table.