In a move that could upset China and South Korea, Prime Minister Shinzo Abe yesterday chose in a Cabinet reshuffle a fiercely nationalistic defence minister with little experience in security issues.

Mr Abe assigned the "heavy responsibility" to lawyer Tomomi Inada, 57, citing her record as policy chief of the ruling Liberal Democratic Party (LDP) for two years.

She becomes the second woman to helm the defence portfolio, following the newly elected Tokyo Governor Yuriko Koike, 64, who took charge briefly in 2007.

But all eyes are now on whether she might be prone to missteps that could upset Japan's delicate ties with China and South Korea.

Ms Inada is a regular visitor to the controversial Yasukuni Shrine, which honours Japanese war dead, including several war criminals.

She visits twice a year - on April 28, which is the date Japan regained sovereignty after World War II, and on Aug 15, which marks the end of the war.

When asked if she will visit the shrine this month, she told reporters: "It's a matter of one's heart, so I will not say if I will go or if I should or should not worship there."

But she added that she will "give my utmost to ensure peace and security by cooperating with nations that share interests and values", citing the Japan-United States security alliance in particular.

Japan is embroiled in separate territorial disputes with China and South Korea. Ms Inada had once been refused entry to South Korea when she tried to visit islands near the Dokdo/Takeshima islets that are claimed by both countries.

Experts said Ms Inada shares Mr Abe's conservative political views, being strongly in favour of revising the post-war Constitution. She had also repeatedly taken up issues such as the Nanjing massacre and the Tokyo war crimes trials.

Prof Jeffrey Kingston, director of Asian Studies at Temple University in Tokyo, said her appointment is "quite counterproductive" to ties with China and South Korea.

He told The Straits Times: "Given that she has a lot of historical baggage, and that she's associated with the revisionist view of history that aims to rehabilitate Japanese imperial aggression, it will not play well in the neighbourhood."

Mr Abe told a news conference yesterday that his new Cabinet is focused on "steadily strengthening ties with neighbouring countries like China and South Korea".

Yesterday's Cabinet reshuffle is Mr Abe's third since he came into power in December 2012, and comes after the LDP won a two- thirds majority in last month's Upper House election.

But he did not make any changes to his core team: Chief Cabinet Secretary Yoshihide Suga, 67, Finance Minister Taro Aso, 75, and Foreign Minister Fumio Kishida, 59.