Cuba denied entry to a Taiwanese mayor and acting chief of its main opposition party earlier this week, her party said Friday.

Chen Chu, mayor of Taiwan's second largest city Kaohsiung and a senior member of the Democratic Progressive Party (DPP), was stopped at Havana airport on Monday, according to the city government.

The other 20 members in her group successfully entered the country, it said, calling the visit the first by a Taiwanese municipal-level delegation.

A DPP spokesman contacted by AFP declined to comment on why Chen had been barred from entering.

China is Cuba's second most important commercial partner after Venezuela and a key source of credit.

Chen, a human rights advocate who served as labour minister during the DPP's years in power from 2000 to 2008, became the party's acting chief following the defeat of its chairwoman and presidential candidate last month.

Tensions with China mounted under the rule of the DPP over its policies promoting Taiwan's independence.

While in opposition, the DPP incurred the wrath of Beijing in 2009 after it invited exiled Tibetan spiritual leader the Dalai Lama, labelled by Beijing a "splittist", to visit the island.

Ex-vice president Annette Lu, also from the DPP and an outspoken critic of Beijing, accused China of blocking her visit to Egypt for an international forum in the same year.

Ties with China have improved markedly since Beijing-friendly Ma Ying-jeou became Taiwan's president four years ago, although China still claims sovereignty over the self-ruled island.

The two sides split in 1949 after a civil war.