"I want to make one thing very clear to the Estonian people today. [The] United States remains steadfastly committed to the freedom and sovereignty of our Baltic allies," Austin said. "And we stand united with you to deter and defend against any threat to our shared security." 

Estonia, Latvia, Lithuania, Poland, Slovakia, Hungary and Romania are neighbors of Ukraine where war is raging. They're NATO members and the United States has bulked up troop presence in the region in response to President Vladimir Putin's unprovoked and brutal war to exterminate Ukraine. The Eastern European nations are among the leaders in supporting Ukraine and providing refuge for the millions of Ukrainians who have fled the Russian invasion. 

Austin stopped in the Estonian capital of Tallinn after attending the NATO defense ministers' meeting and chairing the Ukraine Defense Contact Group in Brussels. He spoke during a news conference with Estonian Defense Minister Hanno Pevkur. 

"Next week, we'll mark a year since Russia launched its full-scale invasion of its peaceful neighbor, Ukraine," Austin said. "And we mourn the lives lost so needlessly in Putin's cruel and unprovoked war of choice. As the Ukrainian people fight so bravely to defend their sovereignty, they remind us that we can never take freedom for granted." 

Estonia understands this to its core, having been occupied by the Soviet Union from 1944 to the dissolution of the autocracy in 1991, Austin said.  

Estonia has been a leader in the effort to turn back Russia and defend the rules-based international order that calls for peaceful settlement of differences and guarantees sovereignty.  

"Our security continues to be guaranteed by our membership in NATO, the most powerful alliance in history," Pevkur said at the news conference. "Last year at the NATO Madrid Summit, allies made historic decisions to make the alliance even stronger. Allies committed to establishing a credible forward-defense posture on NATO's eastern flank in order to ensure that every inch of allied territory is defended without delay." 

At the summit, President Joe Biden announced the decision to enhance the U.S. rotational presence in the Baltic states. "Call that 'promise delivered'," Pevkur said. "A U.S. [High Mobility Artillery Rocket System] platoon and an infantry company are now training side by side with the Estonian Defense Forces increasing interoperability and strengthening the security of Estonia and NATO.  

Russia has launched an offensive in Ukraine with thousands of reserve soldiers that have poured into the conflict and increased rocket attacks on civilian targets in Ukraine. Putin shows no sign of giving up his "imperial ambitions," Pevkur said. He expects more progress in combatting the Russian threat at the NATO Summit in Vilnius, Lithuania, this summer. 

"You've shown tremendous leadership in supporting Ukraine today," Austin said. "As a share of your economic size, Estonia has provided more military aid to Ukraine than any other country in the world. You've made hard decisions to get Ukrainians the assistance that they need to defend themselves. So, thank you for your leadership. It is truly a shining example to all countries."  

NATO is strengthening its deterrence and defense in the eastern part of the alliance, and the United States is among those allies enhancing its presence. "We'll maintain a persistent rotational presence in the Baltics," Austin said. "So, I'm confident that our two proud democracies will work together to meet any challenge, and together will continue to strengthen trans-Atlantic security and to defend the rules-based international order that keeps us all safe." 

Austin said Putin's war strengthened the resolve of NATO members. 

"Putin thought that he could divide NATO, but his aggression achieved just the opposite: The NATO alliance is more united and stronger than I've ever seen it," he said.