"Today we know that we have true friends and allies, and their strong supportive shoulder," she added, speaking alongside top EU officials, presidents and royalty.
Like fellow NATO and eurozone Baltic states Latvia and Estonia, Lithuania increased defence spending and welcomed troops from allies after Moscows 2014 intervention in Ukraine.
Vilnius earlier this month accused Moscow of deploying nuclear-capable ballistic missiles to Russias Kaliningrad exclave on the Baltic.
To demonstrate collective defence commitments, US and Danish fighter jets deployed in Lithuania roared across the capitals cloudy skies on Friday.
"Independent Lithuanias major achievement has been the creation of a genuinely stable democracy," said Vilnius University analyst Kestutis Girnius.
"Although changes in government have been frequent, and populist parties come and go, election results have never been challenged," he told AFP.
Lithuania can also boast solid economic growth of 3.9 percent last year, though it is beset by daily concerns over rising prices, social inequality and emigration to the richer west.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)