A young Islamic State (ISIS) militant with a suspected British accent has reportedly issued a threat to United States President Donald Trump and has warned him of new attacks.

Libyan National Army kills 20 blindfolded 'ISIS fighters', sparking concern [GRAPHIC PHOTOS]

The video, which surfaced recently, shows the ISIS fighter who has been identified as Abu Ishaq al-Somali, wielding a large knife and standing next to a machine gun positioned at a window in an unknown location.

Rome, Istanbul on hit list

The jihadist in the video --  which is of 20 seconds -- has pledged further violence particularly on Constantinople [Istanbul] and Rome.

In the video, the militant who keeps on switching between English and Arabic, looks into the camera and says, "This is a message to the new pharaoh of today, Donald Trump."

"You may have your eyes on Raqqa and Mosul but we have our eyes on Constantinople [Istanbul] and Rome," he said in the chilling video which was first reported by a leading English daily in UK.

"We will slaughter you in your own houses," he added.

According to the Mirror, the video was shot by the militant groups propaganda bureau in Raqqa, which served as a de facto capital of this terror outfit after they took over the city in 2013.

Istanbul terror attack
A man places carnations at the scene of a suicide bombing at Istiklal street, a major shopping and tourist district, in central Istanbul, Turkey March 20, 2016.Reuters

Why the threat

The ISIS militant's outrage comes after US-backed forces have partlty succeeded in wiping out the terror group form the Middle East.

The ISIS fighter's vow to slaughter innocent victims is purportedly in retaliation to the campaigns by the US-backed Syrian Democratic Forces (SDF), who have eliminated hundreds of his group members in Raqqa, Syria, and Mosul, Iraq.

ISIS Militant
Video screengrab

While the Iraqi government had declared their victory in July over ISIS militants' stronghold in western Mosul, reports state that the SDF is on the verge of seizing full control of the Raqqa's southern neighbourhoods.

A coalition spokesman was quoted as saying by the Mirror that the SDF, which includes the Kurdish YPG militia, was making "consistent gains".

The fight to eliminate ISIS militants from Raqqa began in early June.

"We've seen a less coherent ISIS defense in Raqqa compared to Mosul," Coalition spokesman Col Ryan Dillon told Reuters.

mosul
Iraqi Army trying to reach site where ISIS executed dozens of prisoners near Mosul Pictured: Children welcome Kurdish Peshmerga fighters after peshmerga recaptured from Islamic state militant, the Fadiliya village in Nawaran, north of Mosul, Iraq, October 27, 2016.Reuters

"ISIS is still using car bombs, booby traps, and civilians to hide behind, but their inability to address the multiple advances from the SDF is apparent," he added.

This video was released just a few days after the International Police Organization (Interpol) had circulated a list of 173 Islamic State fighters who have been reportedly trained to mount suicide attacks in Europe to avenge their defeat by the Iraqi military forces in the Middle East.