European Union officials have welcomed Lithuania's resounding Yes vote for EU membership in a two-day referendum.
Support for EU entry comes from across Lithuanian society
European Commission president Romano Prodi gave his "sincere and heartfelt congratulations", after unofficial results suggested 91% of Lithuanians supported the move.
There had been concern among the pro-EU factions that voter apathy might mean the required 50% turnout would not be met - but the officials said more than 64% of voters cast their ballots.
Lithuania, a former Soviet republic with a of 3.5 million, is one of 10 mostly ex-communist states hoping to join the 15-nation EU next year.
President Rolandas Paksas
"The Lithuanian voters have made a historic choice over this weekend, one which I am sure is the right one," Mr Prodi said.
Enlargement commissioner Guenter Verheugen noted how much Lithuania had changed since independence from the USSR in 1991.
"It is also amazing and encouraging to see how far and how fast Lithuania has changed," he said.
President Paksas had urged people to vote
"After all, it was only 12 years ago that defensive barricades were still standing outside the parliament in front of Soviet tanks."
Polish Prime Minister Leszek Miller described the result as a "fantastic example" for his country, which faces its own referendum on 7-8 June.
After the first day of voting on Saturday, only 30% of voters had cast their ballots.
But by Sunday afternoon that figure had risen to nearly 60%.
A few hours before the polls closed, the country's staunchly pro-EU leaders began celebrating by throwing a big party at the parliament in the capital Vilnius.
Fireworks lit up the sky, and a big concert was organised near the presidential palace.
"Hello Europeans!" President Rolandas Paksas said as he emerged from his office to address the cheering crowd.
Prime Minister Algirdas Brazauskas and Parliamentary speaker Arturas Paulauskas sliced a referendum cake.
The celebrations lasted well into Monday morning, and people were handed out small flags with the EU stars on one side and the red, green and yellow Lithuanian tricolour on the other.
All major political parties in the Baltic republic are in favour of joining the European bloc.
The BBC's Steve Rosenberg says if Lithuania does join the EU it will have come a long way since 1990 when it was still part of the Soviet Union.
In that same year, the country declared its independence from Moscow.
Lithuania is the fourth EU candidate to hold a referendum on joining, after 10 states were invited last year to join the bloc in May 2004.
Malta, Slovenia and Hungary all voted "yes" earlier this year.