CNN Black Sheep Scott Jennings got into a tense verbal exchange with liberal commentator Adam Mockler during a debate over the war in Iran.

Jennings and Mockler appeared on CNN on Thursday evening during a lively debate over the ongoing war in Iran, as the conservative pundit took aim at the left-winger. 

'I mean honestly they have been at war with us for 47 years,' Jennings began. 

Mockler then chimed in: 'We all know that Scott Jennings is more than happy to defend a war with a country that starts with the letters "Ira" that we are currently failing that is gonna put us trillions and trillions of dollars more in debt.' 

He added: 'I was only a few years old while you were in the administration defending prior endless wars. Now this war is failing.'

'Eight weeks is endless to you?' Jennings asked. 'Is that your- you have the attention span of a gnat?' 

Mockler recalled debating Jennings 'four to six weeks ago,' where Jennings said the war was 'weeks away' from ending. 

'Now you're making condescending remarks because you can't defend the fact that this war is not going your way. Wait, one more time - name one political concession-,' Mockler continued. 

'Get your f***ing hand out of my face,' Jennings snapped at Mockler. 'Honestly, I'm not gonna have this guy's hand in my face.'

'Everybody hang tight,' host Abby Phillip interjected. 

'No. Everybody calm down. Okay? We're having a debate. You can respond to the points that he's making.'

Mockler piped up again and asked if Jennings could name a political concession. 

'We have a very simple goal,' Jennings said. 'To keep terrorists and a terrorist regime from having a nuclear weapon that can threaten the United States, our interest in the region, our allies in Europe, anybody else.'

'So you can't answer the question. I would get mad too,' Mockler chipped in. 

'We're going to leave it there guys,' Phillip said, moving the conversation on. 

The heated exchange comes after Ayatollah Mojtaba Khamenei declared that the 'only place' for the US in the Persian Gulf is at the 'bottom of its waters' as Tehran says the president's naval blockade is 'doomed to fail.'

In a published written message to commemorate National Persian Gulf Day, Khamenei said: 'We are "fellow-destined" with our neighbors in the waters of the Persian Gulf and the Sea of Oman, and the foreigners who wreak their greedy havoc from thousands of miles away have no place there, except at the bottom of its waters.' 

Iran's Supreme Leader claimed a new chapter for the Gulf and Strait of Hormuz has been taking shape without America following what he described as the US's 'shameful failure' over the waterway.

'Today, two months after the largest military deployment and aggression by the world's bullies in the region, and the United States' disgraceful defeat in its plans, a new chapter is unfolding for the Persian Gulf and the Strait of Hormuz.'

Khamenei, who hasn't been seen or heard since he was appointed the supreme leader following the death of his father Ali, also said US bases in the region 'lack even the capacity to ensure their own security, let alone provide any hope of securing their allies.'

It comes as the US military briefed Trump on new plans for potential strikes on Iran aimed at ending the stand-off which has resulted in the effective closure of the Strait of Hormuz to commercial shipping.

On Tuesday, the State Department sent an internal cable to US embassies calling on diplomats to convince governments around the world to join the 'Maritime Freedom Construct,' a US-led bloc to share information, coordinate diplomatically, and enforce sanctions to unblock the vital waterway, the Wall Street Journal has reported.

The coalition will see the State Department serving as a 'diplomatic operations hub' and the US Central Command providing 'real-time maritime domain awareness.'

Another plan that is being discussed is a possible special forces operation to secure Iran's stockpile of enriched uranium.

Trump also warned that a US naval blockade against Iran could last months, leading oil prices to spike to their highest level in more than four years.

International benchmark Brent crude soared more than 7 percent to $126 a barrel on Thursday, but then eased in midday trading in London.

'The world is facing the biggest energy crisis in history,' International Energy Agency chief Fatih Birol said at a high-level meeting on the energy transition at IEA headquarters in Paris, adding that oil prices were 'putting a lot of pressure in many countries'.

Meeting oil executives, Trump contended that the blockade of Iranian ports - which Tehran has demanded must end before any deal - was more effective than bombing.

The President has told national security officials to prepare for a long blockade of Iran's ports in order to compel Tehran to give up its nuclear program, according to the Wall Street Journal.

Trump, according to the report, does not believe that Iran is negotiating in good faith and hopes it can be forced to suspend uranium enrichment for 20 years and accept tight restrictions thereafter.

Iran further threatened to 'respond' if the blockade continues.

On Wednesday, the military adviser to Mojtaba Khamenei reiterated the warning, without elaborating.

'We will not tolerate the naval blockade. If it continues, Iran will respond,' Mohsen Rezaei, a former commander-in-chief of Iran's Revolutionary Guards who was named as a military adviser by Khamenei in March told state television.

He also warned against a new round of fighting between the US and Iran, saying it could possibly see US ships sunk and 'its soldiers will be killed.'

'If the US starts another war, it should expect that we take a large number of them prisoner,' he added.