Balli said the battle aims to eliminate all remaining ISIL militants in Baghouz.
The coalition has been training and providing air support to the Syrian Democratic Forces, which launched an offensive on the last pocket of jihadist territory in September 2018.
SDF official Mustafa Bali, speaking to Reuters, described the assault as "the last battle".
President Donald Trump, who is planning to pull USA forces out of Syria, said on Wednesday he expected an announcement as early as next week that the US -led coalition operating in support of the SDF had reclaimed all the territory previously held by the jihadist group.
In recent months, the SDF forces have launched concentrated efforts, backed by airstrikes by the US-led coalition to rout the remaining fighters from the final patch of territory in Syria's eastern province of Deir Ezzor.
Bali went on to note that over the last 10 days, the SDF had handled the battle "patiently" as residents of villages located near the Daesh enclave near Iraqi border were evacuated.
Russian Federation demands USA destroy missile defence systems in Romania, strike drones
This comes after the United States recently announced the decision to withdraw from the INF Treaty over the next sixth-months. Moscow denies violating the treaty.
The SDF arrested 63 suspected militants in the Syrian city of Raqa Thursday during an operation against jihadist sleeper cells, it said in a statement.
The Britain-based war monitor Syrian Observatory for Human Rights said SDF fighters were advancing "cautiously" due to mines planted by Isis gunmen.
Islamic State leader Abu Bakr al-Baghdadi declared the group's "caliphate" in 2014 in territory stretching across Iraq and Syria.
The conservative chancellor said monitoring events in Syria was one of the BND's top priorities, which also include tracking cyber threats and fake news created to influence democratic elections.
Among the policy decisions still to be made was what to do about the tens of thousands of Syrian Kurdish fighters that U.S. forces had trained, armed and advised to carry out the ground war against the Islamic State.
The U.S. military presence in Syria has offered the Kurds a measure of protection against any Turkish offensive.
Kurdish authorities say they have in their custody hundreds of foreign male ISIS members.