The presidents of Estonia, Latvia and Lithuania on Wednesday marked the 20th anniversary of the Baltic states' accession to the European Union.
"We have experienced enormous economic growth, stability and security, and at the same time represent a remarkable success story of European integration and transformation," the leaders said in a joint statement.
The three nations, which were Soviet republics until 1991, joined the EU on May 1, 2004, alongside Poland, the Czech Republic, Slovakia, Slovenia, Hungary, Malta and Cyprus. It was the largest single round of EU enlargement to date.
"The inscription 'European Union' appeared on our citizens' passports, marking a triumphant return to our rightful historical place as members of the European family," said the statement, which was released jointly by the heads of state of Estonia (Alar Karis), Latvia (Edgar Rinkēvičs) and Lithuania (Gitanas Nausėda).
"Our membership of the EU - and NATO - has fundamentally changed the geopolitical landscape and determined the future of the Baltic states," the leaders added.
Earlier, Estonian Prime Minister Kaja Kallas highlighted the significance of EU membership for her country's security in the wake of Russia's war in Ukraine.
"Today's security situation confirms that belonging to the European Union ensures the survival of our country and helps us to protect our democracy," she said in a video message. "Membership of the European Union and NATO are the cornerstones of our security," she stated.
Estonian Foreign Minister Margus Tsahkna said: "Belonging to the European family has given Estonia the certainty that we will never again stand alone."
"When we emerged from the Soviet prison, we started working straight away to join [the EU] because we knew: Prosperity is security and security is prosperity," Prime Minister Kallas emphasized in her video message.
Estonia's accession to the EU has been "a success story" which now enables the country to support other states such as Ukraine on their path towards EU membership, she added.
Events have been taking place across central and eastern Europe this week to commemorate the anniversary.
Czech President Petr Pavel on Monday hosted his German counterpart Walter Steinmeier for a joint press conference in Prague, while the German and Polish foreign ministers were expected to join festivities in the twin border towns of Frankfurt an der Oder and Słubice.