(CNN)-- Ryan Crocker, a veteran US ambassador who served long periods in the Middle East, including Iraq, Syria and Lebanon, warned that the United States will not achieve its goal of regime change in Iran under current circumstances.

Crocker stated in an interview with colleague Alex Mickelson of CNN that the US position has become "worse" than it was before the outbreak of war with Iran, stressing that this is "beyond doubt."

Archive photo of then-US Ambassador to Iraq Ryan Crocker (right) before a joint hearing of the US House of Representatives with then-US commander in Iraq General David Petraeus, 2007 (Credit: TIM SLOAN/AFP via Getty Images)

Crocker - who survived the bombing of the US Embassy in Beirut in 1983 - pointed out that the goal at this stage should be to open the Strait of Hormuz to all maritime navigation without conditions.

He explained that achieving this requires "a mix of diplomatic efforts, economic pressure, and field military moves," noting that the chances of substantive change in Iran are slim, and that seeking regime change is a very ambitious goal at the present time.

The former US ambassador stated that the top priority lies in returning the United States to the position it was in before the war began, stressing that "Iranians are masters of the art of war," and that continuing fighting for a long time has increased the rigidity of the regime, and that trying to force them to submit through bombing will not work.