The Kurdish-led Syrian Democratic Forces (SDF), with help from USA and British special forces, have made the advances over the weekend and are continuing today.
About 20,000 civilians have been evacuated from the area in the eastern province of Deir-el-Zour over the past few weeks to clear the way for a holds barred onslaught.
Gen. Joseph Votel, the commander of USA forces in the Middle East, estimated there are between 1,000 and 1,500 IS fighters in the small area they still control, but he said others have "dispersed" and "gone to ground".
There are an estimated 500 jihadists are holed up in the 3 square kilometre Baghouz area.
Backed by air strikes, the SDF have driven out IS from towns and villages in north-eastern Syria in recent months. Asked whether the withdrawal of America's more than 2,000 troops would begin in days or weeks, Votel said: "Probably weeks".
Champions League: Cavani injured ahead of PSG's trip to play Manchester United
If we are missing lots of key players, it's an even bigger challenge, but we will be ready on Tuesday, I think". In my opinion, the news will not be good", Tuchel told French TV channel TF1.
ISIL snipers and landmines have slowed a US-backed ground force as it pushes to retake the armed group's last enclave in eastern Syria.
The US military has already started withdrawing equipment from Syria.
Trump announced in December he was pulling all 2,000 USA troops out of Syria, saying the battle against Islamic State there was nearly won.
"After the defeat of ISIS we can not say that the roots of violence and terrorism are over, as ISIS is an ideological status and not only a military structure", Assaad Bechara, political analyst and editor of Lebanon's Al-Joumhouria newspaper, told The Associated Press on Monday.
That's according to a Sunday report by Martin Chulov in the Guardian, which says the secretive leader known as "Caliph Ibrahim" had to fend off a two-day internal assault in September, by foreign fighters within his group who were eager to overthrow him.
The strategy, which the group deployed in Mosul and elsewhere, is presenting a real challenge, SDF commanders said.
Amazon reconsidering Long Island City location, according to report
Contrast the opposition in NY with the welcome in Virginia, and you can see why Amazon executives are reconsidering their choice. Even before these subsidies, New York City has been struggling to fund acceptable public transportation and affordable housing.
At its peak, ISIS held large swaths of Iraq and Syria - an expanse about the size of Portugal.
The SDF managed, with the help of the US, to defeat the IS in much of the areas it had controlled in the eastern Euphrates area.
The YPG fighter, who did not wish to be named, said spotting ISIS militants hidden among the thousands of fleeing civilians is proving hard.
All that is now left of the "caliphate" declared by ISIS in 2014 is a cluster of farmhouses and fields on a bend of the Euphrates River in northern Syria. Including things the United States says it doesn't need. It has sent vehicles into eastern Syria as well as artillery.
US officials have said in recent weeks that IS has lost 99.5 percent of its territory and is holding on to under 5 square kilometers (under 2 square miles), where the bulk of the fighters are concentrated in Syria.
No designated hitter or draft changes likely in Major League Baseball this season
It is customary under present rules for managers to use a relief pitcher for one out, even if that at-bat requires just one pitch. The three-batter minimum and the 12-pitcher limit on rosters would both reduce the frequency of pitching changes.