BRUSSELS

EU foreign policy chief Kaja Kallas on Sunday called on all parties involved in the Iran nuclear issue to de-escalate tensions and resume diplomatic negotiations.

"I urge all sides to step back, return to the negotiating table and prevent further escalation," Kallas said on X.

Kallas also stressed that Iran "must not be allowed to acquire a nuclear weapon," warning that such a development would pose "a threat to international security."

She said EU foreign ministers will discuss the issue during the Foreign Affairs Council on July 23.

The situation in the region further deteriorated after US President Donald Trump announced Sunday that American forces carried out "very successful" airstrikes on three Iranian nuclear sites, amid growing fears of a broader conflict in the region.

Following US strikes, Iran called on the UN Security Council to hold an emergency meeting to condemn the US aggression and to hold accountable those who violate international law.

Hostilities broke out on June 13 when Israel launched airstrikes on several sites across Iran, including military and nuclear facilities, prompting Tehran to launch retaliatory strikes.

Israeli authorities said at least 25 people have been killed and hundreds injured since then in Iranian missile attacks.

Meanwhile, in Iran, 430 people have been killed and more than 3,500 wounded in the Israeli assault, according to the Iranian Health Ministry.