Russia on Monday halted all dairy imports from EU president Lithuania in a trade row over the tiny Baltic state's attempts to draw ex-Soviet nations such as Ukraine closer to the 28-nation bloc.
The Russian agency responsible for overseeing consumer protection rights said it had decided to impose a full import ban due to neighbouring Lithuania's "weak control" over the quality and safety of its dairy products.
"The Russian Federal Consumer Rights Protection and Human Health Control Service is halting the import into Russia of milk and dairy products produced in Lithuania," the agency said in a statement.
Lithuania has lobbied the European Union to respond to arduous customs checks that Moscow has imposed on Eastern European countries now seeking closer relations with Brussels.
Ukraine hopes to sign a landmark association and free trade agreement with the EU during a November summit in Lithuanian capital Vilnius.
But Moscow wants to draw Ukraine into a Russia-led economic union that also includes ex-Soviet Kazakhstan and Belarus.
The row prompted Lithuania to warn Moscow this month that it risked souring ties with the EU if such checks continued.
Lithuania also pointed out that it could -- but would not -- impose the same sanctions on goods travelling over its territory to and from Russia's western exclave of Kaliningrad.
Russia had said over the weekend that it would impose only a partial ban on Lithuanian dairy imports and Monday's decision was tougher than expected.
An unidentified Russian source also told the Prime news agency that Moscow was "strengthening control" over the import of Lithuanian fish and meat.
Another Russian agency overseeing veterinary and phytosanitary surveillance accused the EU itself of adopting weak safety standards "that fail to accurately identify" what feed products go into food production.
The dairy industry -- responsible for about one-fifth of Lithuania's agricultural production -- is a vital part of its export revenue.
Moscow's restrictions would be especially painful because the Russian market accounts for about 85 percent of Lithuania's total dairy exports.
The nation of three million hopes to swap its currency for the euro by 2015 and is keen to avoid any economic shocks that may derail those plans.
Moscow has frequently been accused of using import restrictions as a weapon against ex-Soviet countries seeking greater independence or warmer relations with the West.