Iran’s president, Hassan Rouhani, has called for unity among political factions to overcome conditions that he said may be harder than those during the 1980s war with Iraq, state media reported, as the country faces tightening US sanctions.

Donald Trump on Thursday urged Iran’s leaders to talk with him about giving up their nuclear programme and said he could not rule out a military confrontation.

The president increased economic and military pressure on Iran, moving to cut off all Iranian oil exports while beefing up the US navy and air force presence in the Gulf.

“Today, it cannot be said whether conditions are better or worse than the (1980-88) war period,” Rouhani said, according to the state news agency IRNA. “But during the war we did not have a problem with our banks, oil sales or imports and exports, and there were only sanctions on arms purchases.

“The pressures by enemies is a war unprecedented in the history of our Islamic revolution ... but I do not despair and have great hope for the future and believe that we can move past these difficult conditions provided that we are united,” Rouhani told activists from various factions.