TAIPEI (Kyodo) -- Taiwan's Cabinet has appointed Shigeru Iwasaki, a former chief of the Joint Staff of the Japan Self-Defense Forces, as a political consultant, sources familiar with the matter said Friday, triggering a rebuke from China, which views the self-ruled island as its own.

The appointment marks the second time that a Japanese national has been known to take up the post of adviser to the Executive Yuan, Taiwan's Cabinet, in recent years, following Tainan-based businessman Takao Nozaki, who assumed the post in August.

China lodged a protest with Japan over the appointment of Iwasaki, Chinese Foreign Ministry spokeswoman Mao Ning said at a press conference in Beijing, urging Tokyo to "be careful" with its words and actions regarding Taiwan issues.

"The DPP authorities' collusion with external forces to seek independence and provocation will not succeed," Mao said, referring to Taiwan's independence-leaning Democratic Progressive Party led by President Lai Ching-te, who has been condemned by Beijing as a separatist.

It is rare for a foreigner to be assigned to the role and the decision to choose a former top officer of the SDF appears to demonstrate Taiwan's intent to explore security cooperation with Japan in response to mainland China's military pressure.

Japanese Chief Cabinet Secretary Yoshimasa Hayashi told reporters in Tokyo that he is not in a position to comment on the activities of a person who has retired from public service, but said he is aware of the report about Iwasaki.

Hayashi also said there is no change to the unofficial relations Japan maintains with Taiwan based on the 1972 Japan-China joint communique, which stipulates that Beijing is the only legitimate government of China.

Iwasaki recently visited Taiwan at the invitation of the Executive Yuan and met Premier Cho Jung-tai, according to the sources. During his one-year term, Iwasaki is responsible for making policy recommendations to the Executive Yuan.

After serving as the top officer of the Air Self-Defense Force, Iwasaki worked as the SDF's chief of the Joint Staff between 2012 and 2014.

According to Taiwanese media, Iwasaki made local headlines last May when it was reported that he was attending Lai's inauguration ceremony, a first for a former chief of the Joint Staff of the SDF.