Lithuania said on Monday that Russia was refusing entry to both commercial and private cars and trucks from its territory amid heightened tension over the crisis in Ukraine.
Lithuanian "cars and trucks are virtually not allowed into Russia," Interior Minister Saulius Skvernelis told reporters after a government meeting.
The national road carriers' association in the Baltic EU state said Russia suspended customs procedures for trucks now stuck at the border or at customs points.
"There are a verbal instructions to stop all procedures for cargo from Lithuania and cargo transported by Lithuanian vehicles," association president Algimantas Kondrusevicius told AFP.
Lithuania's foreign ministry summoned the Russian ambassador and demanded Russia "cease immediately the discriminatory practices".
The ministry said it would also turn to the European Commission over the situation.
Vilnius said Moscow imposed restrictions late on Friday, a day after President Dalia Grybauskaite called Russia a "terrorist state" over its role in eastern Ukraine.
Russia's foreign ministry hit back, saying that the remarks "surpassed even the most extremist statements coming from radical nationalists in Kiev".
Former Soviet-ruled Lithuania, which joined EU and NATO in 2004, has been one of the fiercest supporters of Ukraine's integration into the European Union.
Grybauskaite said Ukraine "was battling not only for its own freedom and peace in Europe, but for Europe itself" when she visited visited Kiev on Monday.
According to Lithuania, Russia applied similar customs restrictions for one month last year just before rotating EU president Vilnius hosted a summit at which Ukraine was supposed to ink an association agreement with Brussels, a move Russia vehemently opposed.
The Ukrainian president at that time, Viktor Yanukovych, scuppered the deal at the last minute, sparking Kiev protests that led to his ouster in February.
Lithuania's transport sector is already braced for losses after Russia embargoed EU products amid a sanctions war sparked by the Ukraine crisis.
Blaming the ban, Lithuania's central bank has cut the country's 2014 growth forecast from 3.3 percent to 2.9 percent.