The news was welcomed on Twitter by European Commission President Ursula von der Leyen.
Lithuania will donate 200,000 doses of COVID-19 vaccines to neighbouring countries in the Eastern Partnership.
The initiative was announced by Lithuanian Foreign Minister Gabrielius Landsbergis on Friday, who stated that the Baltic country was ready to "share life-saving vaccines with our eastern partners."
"Today, we have an opportunity to demonstrate the Lithuanian solidarity," he said in a statement.
"The vaccination process in EU countries is fast and smooth, but we are not safe until our neighbours are also safe."
Lithuania plans to allocate 100,000 vaccine doses to Ukraine, 15,000 to Georgia, and 11,000 to Moldova by September, with Vilnius providing "technical coordination" to ensure the first doses arrive as soon as possible.
The Foreign Ministry said they would consider where to distribute the remaining vaccines "in the near future".
"Our partners need a lot of vaccine doses, we hope that other EU member states will follow Lithuania's example," said Landsbergis.
The EU Eastern Partnership association programme also includes Armenia, Azerbaijan and Belarus.
The announcement was welcomed by the European Commission President Ursula von der Leyen, who tweeted her thanks to Lithuanian Prime Minister Ingrida Šimonytė.
"The EU stands by its friends and partners in the Eastern Partnership," said von der Leyen.
Lithuania says their donation will contribute to the Team Europe package, designed to support partner countries in the fight against the coronavirus pandemic and its consequences worldwide.
"Lithuania has consistently raised the issue of the need to facilitate access to vaccines for eastern partners within EU formats and looks forward to working closely with EU institutions in delivering these vaccines to eastern partners," the statement read.