Militants destroyed the Grand al-Nuri Mosque on Wednesday (June 22) evening along with its famous minaret, affectionately called al-Hadba, or "the hunchback" by Iraqis.
Some analysts believe the mosque's destruction could speed up operations to drive IS out of Mosul, while Mr al Abadi said the group's actions amounted to an "official acknowledgement of defeat". It is here where the Islamic State's villain supreme, Abu Bakr al Baghdadi, defiantly declared his Caliphate in 2014 after blitzing across western Syria and much of Iraq.
Initially, ISIS blamed a USA airstrike for the destruction of the mosque.
On Sunday, Iraqi forces backed by USA -led air power advanced against Islamic State amid a push aimed at dislodging the extremist group from the last area under the militia's control in its former stronghold of Mosul. Spokesman, US Army Col. Ryan Dillon told the Associated Press coalition planes "did not conduct strikes in that area at that time".
In doing so, the extremist group justified the destruction on religious grounds-that its harsh brand of Islamic law deems such things heretical.
For Ahmed Saied, a 54-year-old Iraqi schoolteacher, and many others Mosul can never be the same after Islamic State militants blew up up the leaning minaret that had graced his city for almost 850 years.
The Shiite paramilitary force of the Hashd al-Shaabi declared in late April it had fully liberated the town of Hazar, or Hatra, south of Mosul.
The Iraqi military said its counterterrorism forces were within 165 feet of the mosque when it was destroyed.
Iraqi Prime Minister Haider al-Abadi tweeted early today that the destruction was an admission by the militants that they are losing the fight for Iraq's second-largest city.
The tale of mystery began last month, just days after Trump fired Comey, who was then leading an investigation into contacts before and after the election between the president's campaign and Russian officials. They said the militants ordered families to leave the area, likely in preparation for their final stand.
Lt. Gen. Stephen Townsend, the top United States commander in the fight against ISIS in Syria and Iraq, said: "I was just in Mosul Wednesday afternoon and close enough to see the mosque and its famous leaning minaret".
They claimed that as Iraqi forces closed in on the site, IS fighters filled the building with explosives and made a decision to take it down.
The destruction of the mosque and minaret-which has dominated Mosul's skyline for centuries and is pictured on Iraq's 10,000-dinar bank note-is another blow to the city's rich cultural heritage and its plethora of ancient sites that have been damaged or destroyed during three years of IS rule.
ISIS fighters initially attempted to destroy the minaret in July 2014.
Top U.S. commander, Lieutenant General Stephen Townsend, was also quoted to have said: "I was just in Mosul Wednesday afternoon and close enough to see the mosque and its famous leaning minaret".
Iraq's Ministry of Tourism and Antiquities said in 2015 that it had received reports the ancient Assyrian capital of Khorsabad had been destroyed.
Since the launch of the offensive in Mosul in October 2016, around 750,000 to 800,000 people have been displaced from the city; many are trapped or being used as human shields. While Iraqi forces have experienced periods of swift gains, combat inside the city has been grueling and deadly for both Iraqi forces and civilians.
Nabeel Nouriddin, a historian and archaeologist specialising in Mosul and its Nineveh region, said the minaret had not been renovated since 1970, making it particularly vulnerable to blasts even if it was not directly hit. Little did I know it was for the last time.