Lithuania seeks EU protection from Chinese bullying

China did it by recently declining customs clearances in offices in Beijing and Shanghai without any formal notification of sanctions to Vilnius, he added.

The actions took China's "politically-motivated economic pressure to an unprecedentedly high level", he noted.

"These activities ... against one EU member state have a direct impact on the entire EU and our common trade policy. Therefore I would kindly ask you to intervene on behalf of Lithuania with the aim of resolving the present situation," Landsbergis asked the EU institutions.

The covert form of trade sanctions came into being after Lithuania recently invited Taiwan, which China claims as its own territory, to open a "representative office" in Vilnius.

But Beijing's "punishments" began already in August, when Lithuania quit China's "17+1" trade club in central and eastern Europe, Landsbergis also said.

"A strong reaction is necessary at EU level ... to send a signal to China that politically-motivated economic pressure is unacceptable," he said.

For its part, the EU Commission defended Vilnius' Taiwan-office move the same day.

"The EU doesn't think the Taiwan representative office, which is not an embassy or a consulate, should be of any issue," an EU spokeswoman said.

"We'll see if this [Lithuania's customs problem] is a one-off, or if it's systematic. If confirmed, however, we'll have to see if Chinese actions were compatible with WTO [World Trade Organization] rules," she added.

The US, in November, already granted Lithuania a $600m (€571m) export credit agreement to help offset Chinese losses.

But Global Times, a Chinese government mouthpiece, mocked this in a series of stories last weekend.

"This is a drop in the sea," it said on Sunday, noting that Lithuania-China trade was worth over $2bn a year.

"There is no need to let China-EU trade be derailed or hijacked by Lithuania's wanton provocation of China's internal affairs," it added.

"Make no mistake that any country that provokes China's core interests is bound to find itself on the receiving end of countermeasures," it also said.

The aggressive rhetoric comes after China threatened sanctions against the Czech Republic for hosting a Taiwanese VIP in October.

It criticised MEPs who recently visited Taipei.

Slovakia might be next in the firing line, after a 43-member Slovak trade delegation wen to Taipei this week.

And China blacklisted dozens of MEPs and EU officials in retaliation for EU human-rights sanctions in May, sinking a draft China-EU investment treaty.

The Chinese mission to the EU did not reply to EUobserver's questions on Monday.