Neighboring Turkey's Prime Minister Recep Tayyip Erdogan warned that the Iraqi government was steering the country to civil war. Such a conflict could spill across the border.
Peshmerga commander Mahmoud Sankawi said forces were shifted to the Khanaqin area overnight from the nearby town of Kifri. He did not specify how many men or armored vehicles were involved. Sankawi said he did not coordinate with Iraqi forces, nor inform them of the troop movements.
"It is well known to them," Sankawi said.
The Kurdish Peshmerga forces control security in the Kurdish autonomous region, but are also present in disputed areas.
The movement of Kurdish forces came a day after the government sent tanks and armored personnel carriers to the Kirkuk area, some 60 miles away. That area is claimed by both sides.
Tensions have been sharply increasing since Iraqi Prime Minister Nouri al-Maliki formed a new military command last month to oversee Baghdad-run security forces bordering the Kurdish region, including disputed areas claimed by Iraqi Arabs, Turkomen and Kurds—especially the areas surrounding Mosul and Kirkuk.
U.S. forces once supervised the area, helping Kurdish and Arab security forces form joint patrols.
"Now, our fears are slowly coming true," Erdogan said. "The regime is trying to take things toward a civil war."
The Iraqi commander of the newly formed Dijla Joint Military Command, now overseeing government forces in disputed areas, said they would not back down from a confrontation.
"We are closely watching them. We are not afraid of them," said Lt. Gen. Abdul-Amir al-Zaidi. "The Iraqi army must be responsible for Iraqi security and its sovereignty."
Iraqi government officials were unavailable for comment.
On Friday, a shootout between Iraqi police and Kurdish guards in a disputed northern city left a civilian dead and four policemen wounded.
It was the first clash with casualties between the two sides for years, despite disputes over land, natural resources and power sharing since the 2003 U.S.-led invasion that toppled longtime dictator Saddam Hussein.
Additional reporting by Suzan Fraser in Ankara, Turkey.