May 5: The U.S. says it is sending the USS Abraham Lincoln carrier group and a bomber task force to the Middle East because of a ‘credible threat’ from Iran.
Since then Washington has announced the dispatch to the region of an amphibious assault ship, a Patriot missile battery and an extra 1,500 troops.
May 8: Iran vows to enrich its uranium stockpile closer to weapons-grade levels starting July 7 if world powers fail to negotiate new terms for its nuclear deal.
The U.S. responds by imposing fresh sanctions on Iran’s steel and mining sectors.
Smoke pours from the Norwegian-owned oil tanker on Thursday after it was hit by an explosion near the UAE and Iran in an apparent attack which has put the Middle East on high alert
May 12: Two Saudi oil tankers and two other ships are damaged in mysterious ‘sabotage attacks’ off the coast of Fujairah, part of the United Arab Emirates.
Washington believes Iran is to blame for the attacks, but Tehran denies involvement.
May 14: Yemen’s pro-Iranian Huthi rebels carry out drone attacks near Riyadh, shutting down a key Saudi oil pipeline.
Two days later Saudi-led coalition air strikes hit the rebel-held Yemeni capital Sanaa.
The next day the U.S. orders all non-emergency diplomats to leave Iraq, due to an ‘imminent’ threat from Iranian-linked Iraqi militias.
May 19: Trump warns that if Iran attacks American interests ‘that will be the official end of Iran’.
Iranian Foreign Minister Mohammad Javad Zarif says the ‘genocidal taunts’ of U.S. Trump will not ‘end Iran’.
May 27: Trump says the U.S. is ‘not looking for regime change’ in Iran.
May 30: Saudi Arabia – which accuses Iran of being behind the acts of sabotage and the drone attack in May – gets the backing of Arab leaders in its standoff with Tehran at summits organised by Riyadh.
Iran accuses Riyadh of ‘sowing division’.
Inferno: A fire rages on board the oil tanker MT Front Altair after it was hit by an explosion in the Gulf of Oman on Thursday, in what has been described as a torpedo attack
June 6: The UAE says a multinational investigation into the sabotage attacks point to the likelihood a state was behind them, without incriminating Iran.
June 12: Japanese Prime Minister Shinzo Abe arrives in Tehran in a bid to mediate between Washington and Tehran.
A Yemeni rebel missile attack on an airport at Abha, in southwestern Saudi Arabia, wounds 26 civilians. The Saudis accuse Iran of supplying the weapon.
June 13: Two tankers, Norwegian and Japanese, are hit by explosions in apparent attacks in the Gulf of Oman.
The U.S. Fifth Fleet says that it received two separate distress calls from the tankers in a ‘reported attack’.
Foreign Minister Zarif says the tanker ‘attacks’ as Abe visits are ‘suspicious’.
Mr Abe meets Iran’s supreme leader Ayatollah Ali Khamenei who tells him: ‘I don’t consider Trump as a person worthy of exchanging messages with. I have no response for him and will not answer him.’