US-Iran tensions remain high as Tehran warns it will respond to ‘any aggression’, while Trump says the ceasefire is on ‘life support’.

Published On 12 May 2026

Tensions between the United States and Iran remain high as Tehran warned it was prepared to respond to “any aggression” after US President Donald Trump said the fragile ceasefire was on “massive life support”.

Trump on Monday rejected Iran’s latest response to his peace proposal, calling it “stupid”.

Iran’s parliamentary speaker, Mohammad Bagher Ghalibaf, said Iranian forces are ready to retaliate if attacked, warning the US would be “surprised” by its response.

The sharp exchange has deepened uncertainty around efforts to secure a diplomatic breakthrough to end the war that has triggered a global energy crisis. Despite the impasse, Trump has continued to insist that a negotiated solution remains possible.

Here is what to know:

In Iran

• Iranian authorities announced the seizure of six properties allegedly linked to former national football captain Ali Karimi, who lives in exile and has been a vocal critic of Iran.
• The Ministry of Foreign Affairs said Iran called for an end to the conflict and the release of its frozen assets in response to the latest US peace proposal, insisting it was only seeking its “legitimate rights”.

War diplomacy

• Stalled negotiations: Trump rejected Iran’s latest response to the US peace proposal, while Tehran accused Washington of making “unreasonable” demands. He is set to embark on a trip to China on Tuesday to meet President Xi Jinping amid the war.
• Core demands remain unresolved: Trump said his main objective is preventing Iran from obtaining nuclear weapons, claiming Tehran had previously agreed to remove all enriched uranium before reversing its position. Iran has sought “sufficient guarantees” that war will not erupt again, with officials pointing to deep mistrust.
• ‘High likelihood of escalation’: Analyst Dania Thafer said stalled US-Iran talks show both sides are “speaking past each other”, warning pressure tactics such as Strait of Hormuz disruptions could deepen the conflict, damage the regional economy and harden tensions into a prolonged “frozen conflict”.
• Hormuz security meeting: The United Kingdom and France will host defence ministers from 40 countries on Tuesday to discuss plans to restore trade flows through the Strait of Hormuz.
• New US, UK sanctions: The US sanctioned 12 people and entities over Iranian oil sales to China, hours after similar UK measures.

In the US

• Trump dismissed Tehran’s response to the latest US peace proposal as “stupid” and “garbage”, amid fears the conflict could further disrupt shipping through the Strait of Hormuz.
• Al Jazeera’s Mike Hanna said rising diesel costs linked to the war and disruptions in the Strait of Hormuz are pushing up transport and supermarket prices across the US, despite Trump insisting the economic impact will eventually ease.
• Trump said he wants to suspend the federal gas tax to ease pressure from rising fuel prices.

In Israel

• Israel’s civil aviation chief, Shmuel Zakay, warned that heavy US military activity at Tel Aviv’s Ben Gurion airport is disrupting civilian flights, delaying the return of foreign airlines and driving up ticket prices before the busy summer travel season.

In Lebanon

• Lebanese officials urged the US ambassador in Beirut to pressure Israel to halt its attacks on the country, as Israeli strikes continued despite the ceasefire.
• Reporting from Tyre, Al Jazeera’s Obaida Hitto said many residents who recently returned after weeks of displacement are refusing to leave again despite intensifying Israeli attacks, with frustration mounting over repeated displacement, family separation and prolonged disruptions to children’s education.