VILNIUS, Lithuania: China has downgraded its diplomatic ties with Lithuania from ambassador to charge d'affaires level, in retaliation for Lithuania allowing the opening of a Taiwanese representative office.

China has expelled the Lithuanian ambassador and withdrawn its own ambassador, highlighting its intense sensitivity over the status of Taiwan, which Beijing says has no right to conduct its own foreign affairs.

Lithuania's move reflects the keenness of governments to expand their ties with Taiwan, a major trader and center for the high-tech industry, amidst Beijing's increasingly assertive foreign and military policy, which has irritated its neighbors and Western governments.

Taiwan and mainland China have been ruled separately since 1949 after the country's civil war.

The foreign ministry in Beijing accused Lithuania of "undermining Chinese sovereignty and territorial integrity," while calling on the Lithuanian government to "correct the mistakes immediately."

Beijing has persuaded all except 15 countries, mostly small and poor African and Latin American nations, to switch recognition to its government, and refuses to have official relations with governments that recognize Taiwan.

Many governments, including the United States and Japan, have official diplomatic ties with Beijing, while maintaining extensive commercial ties with Taiwan.

By allowing the Taiwanese office in Vilnius to be named Taiwan, instead of Chinese Taipei, a term used to avoid offending Beijing, Lithuania has broken with diplomatic custom.

The Baltic country previously stated it plans to open its own representative office in Taiwan.