Baghdad ? Iraqi Prime Minister Nouri al-Maliki, in an attempt to defuse a major border crisis with Turkey, on Tuesday barred a Kurdish rebel group from operating on Iraqi soil and ordered its offices closed.

“We will work on everything that limits its terrorist activities that threatens Iraq as it threatens Turkey,” al-Maliki announced after meeting with Turkish Foreign Minister Ali Babacan.

The Kurdistan Workers’ Party, or PKK, has openly trained its guerrilla forces in Kurdish northern Iraq, controlled access to the training and operated with relative freedom in the mountainous border region. PKK militants also have mounted guerrilla operations into Iran, through an offshoot called the PJAK. In the last year, U.S. intelligence officials believe the PJAK has killed more than 250 Iranians.

In barring the rebel group from operating on Iraqi territory or maintaining offices in Iraq, al-Maliki applied the label “terrorist.” The PKK has long been on the U.S. list of terrorist groups, but Iraq until now had resisted applying the label. On Tuesday, however, al-Maliki called the group a “bad terrorist organization.”

Tensions between Iraq and Turkey have been rising in recent months due to PKK assaults against military and civilian targets in Turkey.

PKK militants killed at least a dozen Turkish troops and captured another eight in a cross-border raid over the weekend. Turkey has sent troops and armor to the border and has threatened military action to dismantle the rebel group’s operations in Iraq.