President Donald Trump has struck a defiant tone at a White House press briefing, lashing out at reporters who pressed him for a clear end date to the military conflict with Iran.

The President, visibly irritated by persistent questioning, defended his administration's progress by comparing the current six-week campaign to some of the longest engagements in American history.

When asked how long he was willing to wait for a diplomatic response from Tehran, Trump pushed back sharply: 'Don't rush me, Jeff. We were in Vietnam for 18 years. We were in Iraq for many, many years.'

The exchange highlights the growing tension between the White House and the media over the objectives of the Trump-Iran war briefing.

Despite critics raising concerns about the lack of a defined exit strategy, the President insisted that the Iranian military is 'totally defeated' and that his administration is now prioritising a long-term, lasting deal over a hasty withdrawal.

During the briefing on Thursday, the reporters pressed the president on the lack of clarity surrounding a potential end date for the US military campaign in Iran. 'On the war with Iran, how long are you willing to wait until you get a response?' a reporter whom Trump referred to as 'Jeff' asked the US president.

He repeatedly pointed to Vietnam as an example, suggesting that critics were ignoring how long earlier conflicts had taken to resolve. 'Well, don't rush me. Don't rush me, Jeff,' adding that 'We were in Vietnam for 18 years. We were in Iraq for many, many years. We're in for all the... I don't know. I don't like to say World War II because that was a biggie. But we were four and a half, almost five years in World War II. We were in the Korean War for seven years.'

Trump reiterated that he has only been dealing with the conflict for a few weeks. 'I've been doing this for six weeks. And their military is totally defeated,' he said during the briefing.

The exchange escalated as Trump expressed frustration with the line of questioning, reports said, with him appearing visibly irritated as he defended his administration's strategy and rejected pressure to set a fixed timeline for withdrawal or resolution.

When pressed by another reporter, asking, 'What do you say to the American people who question how much longer this will take?' he responded sharply, saying, 'You are such a disgrace. Did you know what I just said? Vietnam. How many years was Vietnam?'

Source: International Business Times UK