Ali Akbar Velayati, senior Iranian statesman and advisor to the office of the supreme leader, warned on March 31 that any ground invasion of Iranian territory would turn the current conflict into a "historic and civilisational" war.

"Any ground invasion by the enemy at any point in Iran will make the sacred Ramadan defence historic and civilisational," Velayati wrote on X, adding that "the nation will turn the Ramadan battle into Xerxes' Battle of Thermopylae."

The statement came in response to repeated threats by US President Donald Trump regarding a possible ground operation against Iran and the occupation of Persian Gulf islands. 

Velayati's invocation of Thermopylae carries pointed historical symbolism. The 480 BC battle saw a small Greek force under Spartan King Leonidas hold the narrow coastal pass against the vast armies of the Persian Achaemenid Empire under Xerxes I for three days before being overrun.

The battle became one of history's most celebrated last stands. By referencing Xerxes, Velayati was drawing on shared Persian imperial heritage to frame any US ground assault as an invasion that would meet the same kind of determined territorial defence, while casting Iran as the defending civilisation rather than the aggressor.

Separately, Lieutenant Colonel Ebrahim Zolfaghari, spokesman for Iran's Khatam al-Anbiya Central Headquarters, said Trump had been pressured by "the terrorist organisation Mossad" into waging war on Iran. Zolfaghari said Iranian fighters "have long been waiting for such actions" and that any invasion or occupation would result in "humiliating captivity" for the aggressors, ISNA reported.

The statement came as the Pentagon prepared for potential weeks of limited ground operations in Iran, according to a Washington Post report on March 29 which said thousands of US soldiers and Marines were arriving in the Middle East for what could become a dangerous new phase of the war.

Trump threatened on March 30 to destroy Iran's civilian energy and water infrastructure if a deal to end the war and reopen the Strait of Hormuz is not reached soon. He told the Financial Times that his "preference would be to take the oil in Iran" and that seizing the Kharg Island export hub remained under consideration.

Iran's Parliament Speaker Mohammad Bagher Ghalibaf issued a similar warning on March 29, accusing Washington of secretly planning a ground attack while publicly pursuing negotiations. Ghalibaf said Iranian fighters were "waiting for American soldiers to enter on the ground" and warned of devastating consequences for any invasion force, IRNA reported.

The Pentagon plans fall short of a full invasion and could involve raids by special operations and conventional infantry troops targeting Kharg Island and coastal sites near the Strait of Hormuz.

White House press secretary Karoline Leavitt said the preparations were intended to give the president "maximum optionality" and did not indicate a final decision had been made.

The foreign ministers of Pakistan, Saudi Arabia, Turkey and Egypt met in Islamabad on March 29 in a push towards diplomacy to end the war, which has now entered its second month. Oil prices stood at around $115 a barrel, up nearly 60% since the start of the war on February 28.

Iran's Ministry of Health has reported 2,076 people killed since the start of the war, including 216 children. At least 25 people have been killed in GCC member states.