Two Americans have been captured among a group of five ISIS fighters in eastern Syria, according to a spokesperson for the Syrian Democratic Forces.

Identified as Warren Christopher Clark of Houston, Texas and Zaid Abed al-Hamid - also originally from the US, but of a location not yet released - the pair were seized alongside other foreign fighters from Pakistan and Ireland.

Their capture came as part of Operation Jazeera Storm, a ploy to decimate the Islamic State's last foothold in northern Syria, according to a statement from the Kurdish-led Syrian Democatic Forces.

Warren Christopher Clark, 34, (left) and Zaid Abed al-Hamid, 35, (right) of Huston, Texas has been apprehended by Syrian forces. A resume and covering letter written by Clarke to ISIS were found last year

According to the New York Times, only four other Americans are known to have been captured alive on the battlefield in both Syria and Iraq.

Only 14 Americans have returned back to the US after leaving to fight for the terrorist organisation, and the successful extradition of Clark and al-Hamid would bring the total to just 16.

In contrast, Britain has seen 'hundreds' of ISIS soldiers successfully extradited back to the country for sentencing, according to a study at George Washington University.

Last year, it was revealed 34-year-old Clark had written a covering letter and sent a resume to the Islamic State, hoping to secure employment as an English Teacher.

The pair were captured as part of Operation Jazeera Storm, which is targeting ISIS' last foothold in northern Syria

In the prospective application, Clark wrote: 'I was born and raised in the United States and have always loved teaching others and learning from others as well.

'My work background is largely in English and I consider working at the University of Mosul to be a great way of continuing my career.'

According to his resume which was find during a raid of an IS safe-house in Iraq, Clark obtained a bachelor's degree from the University of Houston and worked as a substitute teacher for two years in Sugar Land, Texas.

He then moved to Saudi Arabia to work as an English teacher, before undertaking the same role in Turkey for three months.

Concluding in 2015, it's believed Clark joined ISIS around that time.

Written under the pseudonym Abu Muhammad, Clark's prospective application was sent in the hope of securing employment within IS as an English teacher

The Houston-native worked as a substitute teacher for two years, before moving to Saudi Arabia and then Turkey in 2015. It's then he's believed to have joined ISIS

Few details have been released so far about al-Hamid, who is said to be 35.

Speaking to Fox News, Pentagon spokesperson Sean Robertson said: 'We are aware of open source reports of reportedly American citizens currently in custody who were believed to be fighting for ISIS.

'However, we are unable to confirm this information at this time. The incident is under investigation.'

On December 19, President Trump announced that US soldiers would be withdrawn from Syria under the pretense that ISIS had been 'defeated' in the region.

However, yesterday the BBC reported that two British soldiers had been 'seriously injured' in a IS-led missile strike on Saturday morning.

The President's spontaneous announcement prompted the resignation of defense secretary Jim Mattis, along with the White House’s senior envoy to the fight against ISIS, Brett McGurk.

President Trump announced the immediate withdrawal of US Troops from Syria last month, but that plan appears to have now stalled

Department of Defense chief of staff Kevin Sweeney also resigned from his post on Saturday evening.

Trump's initial claims of an immediate withdrawal have now appeared to stall, after the president's national security adviser, John Bolton, admitted on Sunday that there's no timeline in place for the exodus and there's a number of conditions that must to be met first before the exit can commence.

'There are objectives that we want to accomplish that condition the withdrawal,' Bolton told reporters.

'The timetable [of the withdrawal] flows from the policy decisions that we need to implement.'

White House national security adviser John Bolton has now revealed the once hasty exit plan is subjected to a number of conditions before it can commence

Trump's spontaneous announcement has been followed by the resignations of defense secretary Jim Mattis (left) and Kevin Sweeney (right)

One of the key conditions, Bolton went on to explain, was to ensure the safety of the Kurdish militias who have been instrumental in the US' efforts to eradicate Syria of ISIS.

However, Turkey considers the Syrian Kurdish forces to be a terrorist group linked to an insurgency within its own borders.

Ahead of his meeting with Turkish officials on Monday, Bolton said he will seek 'to find out what their objectives and capabilities are and that remains uncertain.'

According to Bolton, Trump has vehemently stated he will not allow Turkey to attack the Kurds. 'That's what the president said, the ones that fought with us.'

According to Bolton, the President has vehemently stated that the Turkish military should not attack any Kurdish allies, who assisted the US in the war against ISIS

Bolton said the US has told its Kurdish allies to 'stand fast now' and refrain from seeking protection from Russia or Syrian President Bashar al-Assad's government.

'I think they know who their friends are,' he added.