Kurdish Peshmerga forces are now within 5 miles of Mosul and have cordoned off eight villages of the city, which is currently held by the Islamic State or ISIS, commanders said Sunday.
The Peshmerga said in a statement that the area they cordoned off measures approximately 38 square miles.
They also secured a "significant stretch" of the Bashiqa-Mosul highway to limit ISIS' movements and to prevent the extremists from sending reinforcements.
The statement also noted that eight car bombs were destroyed, three of which were destroyed by U.S.-led coalition aircraft.
"Dozens" of ISIS militants were reportedly killed in the operation.
The offensive near the town of Bashiqa comes nearly a week after Iraq announced its Mosul offensive.
Maj. Gen. Haider Fadhi, said Bashiqa is encircled thanks to the Iraqi and Kurdish forces approaching from the north, east and south.
The town of Bashiqa is located near a military base where approximately 500 Turkish troops are training Sunni and Kurdish fighters for the offensive.
The presence of the Turkish troops has angered Iraqi officials, who say they never gave them permission to enter the country. Iraq has called for Turkey to withdraw its troops, but Turkey has refused, saying its forces will play an important role in retaking Mosul.
U.S. Defense Secretary Ash Carter visited both countries recently and announced an "agreement in principle" for Turkey to help with the offensive.
However, Iraqi Prime Minister Haider al-Abadi told Carter Saturday that this is an "Iraqi battle."
Iraqi troops, the Peshmerga, Sunni tribal fighters and state-sanctioned Shiite militias are all taking part in the offensive, which many fear could lead to tensions among Iraq's different religious communities.
The United Nations agency for children, meanwhile, is concerned over the more than 4,000 people who have fled since the offensive began.
UNICEF's Iraq representative, Peter Hawkins, said children around Mosul are at risk because of the fighting.
The Associated Press contributed to this report.