Iraqi Kurdish leader Massoud Barzani has commanded Peshmerga forces to "deal a death blow" against militants led by the Islamic State of Iraq and the Levant, who have seized large swathes of the country Anadolu Agency reported
The president of the Kurdish Regional Government (KRG) said in a written statement on Monday that Peshmerga fighters had launched an offensive earlier in the day and were advancing on ISIL-held regions.
Barzani said: "We ordered Peshmerga commanders to fight against enemies of the Kurdish people.
"We will attack to strike the death blow to our enemies."
Barzani maintained that "terrorists" had forced Kurds into a war, despite the Kurdish region having maintained a defensive position after ISIL seized the city of Mosul in early June.
Armed groups linked to ISIL captured the Peshmerga-controlled towns of Sinjar and Rabia in Mosul on Sunday, as well as some nearby villages, leading thousands of Iraqis - including Turkmens, Arabs and Yazidis - to flee the town and wait in long queues to enter the Kurdish autonomous region's capital, Erbil.
The Kurdish leader promised not to leave any acre of Kurdish land to militants and to protect Mount Sinjar near the Syrian border, as well as the Yazidi people taking shelter there.
Barzani said they were left alone in their "fight against terrorism" and called for a related international effort and initiative.
Iraqi Prime Minister Nouri al-Maliki earlier on Monday ordered the Iraqi air force to provide air support for Kurdish Peshmerga forces as they battle militants linked to ISIL.
The military co-operation between the federal government and the Kurdish region comes after ISIL secured several victories against Peshmerga fighters over the weekend.
The European Union's Foreign and Security Policy Chief, Catherine Ashton, also called on Baghdad and Erbil to urgently restore their security cooperation in order to confront ISIL.
Meanwhile, fresh clashes between Iraqi government forces and ISIL-led militant groups left 20 militants and two soldiers dead and another four wounded across the country.
Ten militants and one soldier were killed in early morning battles between Iraqi security forces supported by warplanes and militants in the Turkmen town of Amirli in Tikrit city, said the Salah ad din Operations Command.
Six other militants and one Iraqi soldier were also killed in Tikrit's southern Rufayat region.
Separately, clashes in the Iraqi capital of Baghdad left four militants dead.
"Thirteen mortar shells have been capsized in Abu Gurayb region. We also seized scores of other weapons and ammunition," said a statement from Baghdad Operations Command.
Militants led by ISIL and backed by tribal fighters, seized Iraq's second-largest city Mosul on June 10 and captured a number of other cities in the north, including Tikrit and Tal Afar.
They also reportedly control Al Qaim, Rawah, Anah, Al Ratba and Haditha in the western province of Al Anbar.
ISIL armed groups also extended their grip along Iraq's Syrian and Jordanian border on Monday after taking control of border crossings, according to Farhan Ftikhan, the mayor of Al Qaim.
Around one million civilians have been displaced so far amid the ongoing clashes in the country.