Ukrainians celebrated the first day of visa-free travel to the European Union Sunday in what President Petro Poroshenko called "a final exit of our country from the Russian empire."
"The visa-free regime for Ukraine has started! Glory to Europe! Glory to Ukraine!" he tweeted from his official account Sunday morning.
The arrangement will allow Ukrainians with biometric passports to enter all EU member states other than Britain and Ireland for up to 90 days every six months for tourism or to visit family and friends.
Poroshenko met with Slovak counterpart Andrej Kiska Saturday on their common border, opening a symbolic "door to the EU."
"Welcome to Europe," Kiska told a crowd. "I want to call on you to continue carrying out reforms."
Thousands of Ukrainians had crossed into EU countries by midday, according to the Ukranian Foreign Ministry's consular department.
"#Bezviz [no visa] is just the beginning!" Foreign Minister Pavlo Klimkin wrote on Twitter, accompanied by photos of himself crossing the border into Hungary.
The EU approved the arrangement last month after repeated delays since it promised to cement ties with Kyiv in 2014. Ukraine that year became the scene of the worst confrontation between Russia and the West in Europe since the Cold War, with Moscow annexing Crimea and backing separatist rebels in the east of the country.
Visa-free travel is seen as a step toward Ukraine's accession to the European Union, though major hurdles remain based on economic instability and fears of furthering escalating the conflict with Russia.