DAMASCUS, Syria>> Syria’s interim government signed a deal Monday with the Kurdish-led authority that controls the country’s northeast, including a ceasefire and the merging of the main U.S.-backed force there into the Syrian army.

The deal is a major breakthrough that would bring most of Syria under the control of the government, which is led by the Islamist group Hayat Tahrir al-Sham that led the ouster of President Bashar Assad in December.

The deal was signed by interim President Ahmad al-Sharaa and Mazloum Abdi, the commander of the U.S.-backed, Kurdish-led Syrian Democratic Forces.

The deal to be implemented by the end of the year would bring all border crossings with Iraq and Turkey, airports and oil fields in the northeast under the central government’s control. Prisons where about 9,000 suspected members of the Islamic State group are also expected to come under government control.

Syria’s Kurds will gain their “constitutional rights” including using and teaching their language, which were banned for decades under Assad. Hundreds of thousands of Kurds who were displaced during Syria’s nearly 14-year civil war will return to their homes.

The deal also says all Syrians will be part of the political process, no matter their religion or ethnicity.

Syria’s new rulers are struggling to exert their authority across the country and reach political settlements with other minority communities, notably the Druze in southern Syria.

Earlier Monday, Syria’s government announced the end of the military operation against insurgents loyal to Assad and his family in the worst fighting since the end of the civil war.

The Defense Ministry’s announcement came after a surprise attack by gunmen from the Alawite community on a police patrol near the port city of Latakia on Thursday spiraled into widespread clashes across Syria’s coastal region. The Assad family are Alawites.

Though the government’s counter-offensive was able to largely contain the insurgency, footage surfaced of what appeared to be retaliatory attacks targeting the broader minority Alawite community, an offshoot of Shia Islam whose adherents live mainly in the western coastal region.

The Syrian Observatory for Human Rights, a Britain-based war monitor, said 1,130 people were killed in the clashes, including 830 civilians. The Associated Press could not independently verify these numbers.