Turkish leaders say they will not tolerate Kurdish rebel attacks from neighbouring Iraq and will do whatever is necessary to stop them.
Turkish generals were summoned to the crisis meeting
The strongly worded statement came after a Kurdish attack from Iraq in which 12 Turkish soldiers were killed.
In clashes following the ambush near the Iraqi border, 32 PKK rebels were killed, the military said.
Security officials, ministers and top generals met on Sunday night to discuss whether to attack PKK bases in Iraq.
But despite a strongly worded statement, they did not imply an attack was imminent, a BBC correspondent says.
Turkish Prime Minister Recep Tayyip Erdogan said that US Secretary of State Condoleezza Rice had asked Turkey not to take action for a few days.
This, he said, was a sign that Washington was taking Turkey's concerns very seriously.
Turkey has requested that US and Iraqi forces root out PKK rebels from the mountains in Kurdish northern Iraq.
On Wednesday, MPs voted overwhelmingly in support of a motion to allow the military to launch offensives across the border.
It followed an escalation of raids by the PKK - the Kurdistan Workers' Party - as part of its armed campaign for Kurdish autonomy.
Recent attacks blamed on the group have left more than 40 Turkish soldiers and civilians dead.
"Although it respects Iraq's territorial integrity, Turkey will not tolerate that terrorism be aided and abetted and will not be afraid to pay, whatever the price may be, to protect its rights, its indivisible unity and its citizens," said a statement issued after the emergency meeting on Sunday.
"The fight against the separatist terrorist organisation will be waged with determination until the very end," the statement said.
In the latest attack shortly after midnight on Saturday, a large group of PKK rebels crossed the border from Iraq and staged their ambush near the village of Daglica in Hakkari province, the Turkish military said.
The army said it sent reinforcements and helicopters to the area, fired artillery and launched retaliatory attacks in which 32 guerrillas were killed.
The guerrillas said they had captured several soldiers, but this was denied by the government.
Not far from the scene of the fighting, a minibus was later caught in a landmine explosion, also blamed on the PKK, that injured 10 civilians, the state news agency Anatolia said.
Thousands of Turks joined protests in several cities denouncing the attacks and calling for action against the PKK.
About 3,000 PKK fighters are believed to be based in northern Iraq near the Turkish border, says the BBC's Sarah Rainsford in Istanbul.
Formed in late 1970s
Launched armed struggle in 1984
Dropped independence demands in 1990s
Wants greater autonomy for Turkey's Kurds
Leader Abdullah Ocalan arrested in 1999
Ended five-year ceasefire in 2004
There have been regular clashes in the area since earlier in the year, but the latest attack was one of the deadliest for some time, increasing the pressure on the government from the public and the military for a tough response, our correspondent says.
The United States, Turkey's Nato ally, has called for restraint, fearing that any incursions would destabilise Iraq's most peaceful area - the autonomous Kurdish region in the north.
Iraq, too, has urged Turkey not to strike across the border.
Iraq's president on Sunday called on the PKK rebels to lay down their arms, or to leave Iraq.