TEHERAN: Iran warned on Sunday that any renewed war with the United States could last longer than the previous round of fighting, after President Donald Trump said he still had to "take care" of more targets.

Diplomatic efforts to end the Middle East war have been punctuated by repeated threats from the US and Israel to resume bombardments as they hold crucial elections.

"A potential future war could last longer than previous conflict, and the American president would not be in a position to dictate the timing or the conditions of its conclusion," said army spokesman Mohammad Akraminia, according to Iranian state television.

In the most intense phase of the war, which began on Feb 28 with US-Israeli strikes on Iran, Teheran retaliated with missile and drone attacks across the region. Iran-aligned armed groups joined the fighting in Lebanon and Yemen.