Estonia, Latvia, Lithuania, Poland and other Allies agreed to hold consultations under NATO's Article 4 on Thursday morning after Russia attacked Ukraine.
Prime Minister Kaja Kallas said: "The most effective response to Russia's aggression is unity.."
She said there is no direct military threat to Estonia's security and the country's external borders are calm.
"The government has prepared for this crisis, we are monitoring the situation all the time and ensuring people's safety," she said in a statement.
"Russia's widespread aggression is a threat to the entire world and to all NATO countries, and NATO consultations on strengthening the security of the Allies must be initiated to implement additional measures for ensuring the defense of NATO Allies."
During the discussions, the Ministry of Foreign Affairs will present Estonia's views about how to strengthen NATO's deterrence and defense stance in the Baltic region. The Ministry of Defense will do the same.
Under Article 4 of the NATO Agreement, the allies can hold consultations whenever they feel the territorial integrity, political independence or security of any ally is threatened.
A meeting of EU heads of states and governments will be held in Brussels this evening.
Before the government sent its statement, Minister of Defense Kalle Laanet (Reform) confirmed to ERR Russia had launched a large-scale military operation against Ukraine.
"As a result, we are discussing with our allies how to behave. A government meeting is underway and we are discussing the implementation of NATO Article 4," he said, speaking about Estonia's first steps.
#Estonia unequivocally condemns #Russia's military attack on #Ukraine and we have decided to launch #NATO consultations under Article 4 of the North Atlantic Treaty with Latvia, Lithuania, Poland and other Allies.https://t.co/n8hvt1XSMa pic.twitter.com/tCPPCGxHA1— Estonian Government (@EstonianGovt) February 24, 2022
What is Article 4?
Article 4 of NATO's founding treaty says: "The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened."
Any member country can formally invoke Article 4. As soon as it is invoked, the issue is discussed and can potentially lead to some form of joint decision or action on behalf of the alliance.
Whatever the scenario, fellow members sitting around the Council table are encouraged to react to a situation brought to their attention by a member country.
Since the Alliance's creation in 1949, Article 4 has been invoked six times.
Editor's note: This article was updated to add additional quotes from Kaja Kallas.
Editor: Helen Wright