AN SAS sniper killed an ISIS terrorist from almost 2.4km away using a mega-powerful rifle, a report says.

The Sun reports, it took three whole seconds for the bullet to reach the terror thug in Mosul, Iraq two weeks ago.

A veteran sniper hit the insurgent in the throat as he tried to escape a burnt-out building, killing him almost instantly, the Daily Star said.

It is believed to be one of the most difficult long-range kills in the elite regiment’s history.

The paper claimed the shot was fired from a CheyTac M200 — a record-breaking US-made rifle with a max range of up to nearly 3.2km.

It was reportedly on loan to the British army as part of a battlefield trial.

The kill shot was made after a four-hour game of cat and mouse ended when the ISIS terrorist, himself a sniper, let his guard down as he moved between positions, a source told the paper.

“It was a classic counter-sniper operation”, they said.

“The SAS team had him in their sights on several occasions but did not have the time to get a shot off.

“At such a long range there are so many factors which can affect the flight of the bullet.

“The distance was so far that it took almost three seconds for the bullet to hit the target”.

The report comes after US President Donald Trump implored Saudi Arabia and other Middle Eastern countries to extinguish “Islamic extremism” emanating from the region, describing a “battle between good and evil” rather than a clash between the West and Islam.

Veteran Iraqi sniper taking on ISIS says he's killed 173 jihadis Veteran Iraqi sniper taking on ISIS says he's killed 173 jihadis

In a pointed departure from his predecessor, Trump all but promised he would not publicly admonish Mideast rulers for human rights violations and oppressive reigns.

“We are not here to lecture — we are not here to tell other people how to live, what to do, who to be, or how to worship,” Trump said, speaking in an ornate room in the Saudi capital.

“Instead, we are here to offer partnership — based on shared interests and values — to pursue a better future for us all.”

The president’s address was the centrepiece of his two-day visit to Saudi Arabia, his first overseas trip since his January swearing-in.

For Trump, the trip is a reprieve from the crush of controversies that have marred his young presidency and an attempt to reset his relationship with a region and a religion he fiercely criticised as a candidate.

This article first appeared in The Sun and is republished here with permission.