Turkey's cabinet has voted to allow the army to enter Iraq in pursuit of Kurdish rebels, Turkish Prime Minister Recep Tayyip Erdogan has announced.
The US has agreed to share intelligence with Turkish troops
He gave no indication as to whether the decision meant that a military operation was now imminent.
Mr Erdogan says Turkey needs to be able to respond to a recent rise in bomb attacks blamed on PKK rebels from Iraq.
In October, the Turkish parliament voted overwhelmingly to allow military operations to go ahead.
Troops on the border
Speaking on Turkish television, Mr Erdogan said "Turkish armed forces are now authorised for a cross-border operation."
His cabinet had approved the decision in a meeting on November 28, he said.
Turkey has amassed some 100,000 troops on its border with Iraq since October 17 when Turkish MPs voted by 507 votes to 19 in favour of military action.
US President George W Bush held emergency talks with Mr Erdogan in early November in an attempt to avert a large-scale Turkish incursion into Iraq.
At the meeting, President Bush offered to share intelligence about the PKK with the Turkish government and pledged to put pressure on the autonomous government in Northern Iraq to crack down on the rebels.
Kurdish rebels have killed dozens of Turkish soldiers and civilians in the past few month.
The PKK - which is treated as a terrorist organisation by Turkey, the EU and US - has waged a violent campaign for Kurdish autonomy since 1984, resulting in more than 30,000 deaths.