Lithuania has told the Russian region of Kaliningrad that it will block the import and export of a large number of goods by rail because of Western sanctions, the regional governor said on Friday.

The region - home to the Russian Baltic Fleet and a deployment location for nuclear-capable Iskander missiles - is sandwiched on the Baltic coast between Lithuania and Poland, both Nato members, and has no land border with Russia.

Governor Anton Alikhanov said the clampdown would affect between 40 percent to 50 percent of the products that are imported to and exported from Russia through Lithuania.

"We consider this to be a most serious violation ... of the right to free transit into and out of Kaliningrad region," he said in an online video posting, adding that authorities would press to have the measures lifted.

Among the goods that would be affected are building materials, cement and metal products, he said.

Neither Lithuanian state railways nor the Lithuanian foreign ministry were immediately available for comment.

The move could increase already high levels of tension between Russia and Nato over Russia's invasion of Ukraine in late February.

Alikhanov posted what he said was a document from the Lithuanian state railway to its Kaliningrad counterpart saying the clampdown would start at midnight Vilnius time on Saturday (2100 GMT Friday).

He said if the region were not able to have the measures lifted quickly, it would start discussing the need for more ships to carry goods to Russia.

In February, Lithuania closed its airspace to flights from Russia to Kaliningrad, forcing commercial carriers to take a longer route out over the Baltic Sea. (Reuters)