China has already downgraded diplomatic ties with Lithuania and stopped issuing visas in the Baltic EU state in protest.

"We regret the decision of the Chinese authorities," Lithuanian President Gitanas Nauseda told reporters.

Several Lithuanian companies and business leaders complained that their goods were not clearing customs in China.

Vidmantas Janulevicius, president of Lithuanian Confederation of Industrialists, told local media he knew of five companies facing such a problem.

"Lithuania is excluded from the customs system. It seems that such a country does not exist in the Chinese customs system anymore," Janulevicius said.

The foreign ministry said in a statement that it would seek a European response.

"Next week Lithuania will officially ask European Commission to get involved in defending Lithuania's interests over China's decision to stop accepting Lithuanian products," it said.

The row centres on Vilnius's decision to allow Taiwan to open a representative office under its own name.

Beijing baulks at any official use of the word Taiwan, lest it lend a sense of international legitimacy to the island, which China considers part of its territory.

The opening of the Vilnius office is the latest sign that some Baltic and central European countries are seeking closer relations with Taiwan, even if that angers China.

In May, Lithuania announced it was quitting China's 17+1 cooperation forum with central and eastern European states, calling it "divisive".