HAMILTON, Canada

UN Secretary-General Antonio Guterres expressed deep regret Saturday for the failure of diplomacy following US and Israeli strikes against Iran.

"International law and international humanitarian law must always be respected," Guterres said at a Security Council emergency meeting, stressing that "we are witnessing a grave threat to international peace and security."

"Military action carries the risk of igniting a chain of events that no one can control in the most volatile region of the world," he said.

Stressing that there is "no viable alternative to the peaceful settlement of international disputes," Guterres noted that "genuine dialogue and negotiations" are the only way for a lasting peace.

Citing the latest round of US-Iran nuclear talks, which concluded Thursday in Geneva, Guterres said, “I deeply regret that this opportunity of diplomacy has been squandered."

Following the latest talks, both sides had described the atmosphere as serious and constructive under Omani mediation.

"The alternative is a potential wider conflict with grave consequences for civilians and regional stability," he said, urging all parties to "return immediately to the negotiating table, notably on the Iranian nuclear program."