The Turkish parliament on Saturday approved a one-year extension of a mandate to use troops abroad in Syria and Iraq, two days before Iraq's Kurdish region is due to hold a controversial independence referendum.
The bill was overwhelmingly passed. Defence Minister Nurettin Canikli said the extension was intended to protect Turkey from "threats", adding that the Kurdish Regional Government's planned vote on Monday was a "threat to national security".
The mandate had been due to run out on October 30.
Ankara has repeatedly warned Arbil of the "heavy cost" of the poll, while Iraq, Iran and the United States have urged the KRG against the non-binding September 25 vote.
Canikli said the vote demonstrated "an abdication of reason" and Turkey viewed any referendum like this as "null and void".
He added: "We are taking the necessary measures and will continue to do so."
Earlier, Turkish Prime Minister Binali Yildirim warned Ankara's actions in response to the vote would have "diplomatic, political, economic and security dimensions".
When asked whether a cross-border operation was among the options, Yildirim said "naturally" but "it is a question of timing as to when the security, economic and political options will be applied."
The mandate, first approved by parliament in October 2014, has been renewed every year since then.
It allows military action in Turkey's two southern neighbours against Islamic State (IS) extremists and other groups deemed by Ankara to be terror organisations.
Parliament had been due to return from the summer break on October 1.
The Turkish army on Monday begun a military drill close to the Iraqi border and on Saturday, the armed forces said the "exercise continued with the participation of additional troops".
Turkey with Iran and Russia agreed this month "to allocate" their forces to patrol the zone covering rebel-held Idlib province in northwestern Syria and parts of the neighbouring Latakia, Hama and Aleppo regions to ease the six-year conflict.
Previously Turkey launched an operation in Syria in August 2016 to support Syrian opposition fighters against IS jihadists and a Kurdish militia, which ended in March.
Iraq's chief of staff General Othman al-Ghanimi on Saturday met with his Turkish counterpart General Hulusi Akar in Ankara to discuss the "illegitimate" referendum among other issues, the Turkish military said.
Iraqi Kurdish leader Massud Barzani on Saturday delayed a scheduled news conference on the referendum as international pressure mounts for a postponement.