Cavusoglu's remarks came amid an ongoing non-binding referendum on independence in northern Iraq, which will see Kurdish Regional Government (KRG)-held areas, including territories disputed between Erbil and Baghdad, vote on seceding from Iraq.
"Turkish army will intervene immediately if our Turkmen brothers [in disputed Kirkuk province] are physically targeted," Cavusoglu said in an interview aired live on AHaber news network.
Citing Turkish parliament's decision on Saturday to extend the mandate to deploy troops in Iraq and Syria, he also said "all means of action can be taken, if necessary".
The foreign minister said the KRG's independence referendum is "against the constitution of Iraq".
"Turkey considers the referendum as null and void. As the Foreign Ministry, we have already released a statement as soon as the voting began for the referendum," he said.
Cavusoglu reminded the risks that may emerge in the region due to the referendum, saying the poll would not give any rights to the Kurds in northern Iraq and they might even end up loosing their current rights.
Nothing will be the same as before if the KRG does not listen to Turkey's advices and warnings, the Turkish minister said.
Peshmerga training to end
"There will of course be steps taken and we are considering those options. Once decided, we will share with the public and with the world... This referendum essentially shows the Kurdish Regional Government is waiving its constitutional rights," Cavusoglu said.
Emphasizing there will be consequences for KRG's referendum decision, he said Turkey would no longer provide "military training support to the Peshmerga forces," adding Ankara would from now on engage primarily with the Baghdad administration.
"There is no legitimacy in steps taken alone. The Iraqi constitution has already said it is illegitimate. These lands are essentially Iraqi government's lands," he said.
Iraq, Turkey, Iran, the U.S., and the UN have all spoken out against the KRG referendum, saying it will only distract from the ongoing fight against Daesh and further destabilize the region.
Iraq’s central government has threatened to intervene militarily if the vote leads to violence.
KRG President Massoud Barzani has said a Yes win would not result in an automatic declaration of independence but would simply lead to further negotiations with Baghdad.
About the recent Russian airstrikes on Syria's northwestern Idlib province, Cavusoglu said any attack on civilians in the region would be a violation of the cease-fire, as well as a termination of Astana agreement, referring to a series of Syria peace talks held in the Kazakh capital among guarantor states of Turkey, Russia and Iran, as well as representatives of the Damascus-based regime and some opposition faction.
The first round of peace talks was held in the Kazakh capital on Jan. 23-24 after a cease-fire was hammered out on Dec. 30. A seventh round is scheduled to take place in October.
Turkey backs the Syrian opposition, while Russia and Iran support the Assad regime.
Cavusoglu also confirmed that Russian President Vladimir Putin's expected visit to Turkey ahead of President Recep Tayyip Erdogan's visit to Iranian capital Tehran on Oct 4.
He also touched upon Sunday’s election results in Germany, saying: "The center parties have now seen that an anti-Turkey rhetoric or populist approach has no benefit. I hope they have learnt their lesson."
Underlining that Turkey desires to maintain and develop normal, good relations with Germany at all times, he said: "Germany can only get Turkey's support through friendly and sincerely approach, and not by patronizing [us]."
Cavusoglu said bilateral relations between Turkey and the United States is not at the desired level.
"The U.S. is yet to take the necessary steps that we are expecting from them. The U.S. is providing more than 3,000 truckloads of arms to the YPG, which is a serious disappointment for us," he said.
Turkey, along with the U.S. and EU, considers the PKK -- of which the PYD is an offshoot -- a terrorist organization.
Following a year-long hiatus, the PKK resumed its armed campaign against Turkey in 2015. Since then, it has been responsible for the deaths of some 1,200 Turkish security personnel and civilians, including women and children. Yet despite the PKK’s terrorist activities, the U.S. has continued to support the PYD, the PKK’s affiliate in Syria.