A train carried cement from Russia to its Kaliningrad exclave Tuesday, the governor said, in the first such trip since the European Union said Lithuania must allow Russian goods across its territory.

"It is indeed the first train to have arrived after the EU decision," the TASS news agency cited regional governor Anton Alikhanov as saying.

It is "quite an important achievement", he said.

Wedged between Lithuania and fellow EU and NATO member Poland, Russia's heavily militarised exclave of Kaliningrad depends on mainland Russia for a sizeable portion of its supplies. But these must transit through Lithuanian territory.

The region roughly half the size of Switzerland, with around one million inhabitants, has found itself increasingly isolated since Russia sent troops into Ukraine in February.

Vilnius last month said it was banning the rail transit of certain Russian goods across its territory, as an application of EU sanctions against Russia over its military operation.

Alikhanov at the time said the "blockade" could affect up to 50 percent of the exclave's imports, including coal, metals and construction materials.

But the European Union this month said Lithuania had an obligation to allow the passage of sanctioned goods, with the exception of weapons, between mainland Russia and Kaliningrad.

Seized by the Red Army from Germany in the closing stages of World War II, Kaliningrad was separated from the Russian mainland following the break-up of the Soviet Union when Lithuania became an independent state.

bur/ah/kjm