Caroline Kennedy Japan
JFK's daughter Caroline Kennedy takes up role as US ambassador to Japan in Tokyo (Reuters)

The daughter of late US president John F. Kennedy has arrived in Tokyo to take up her new role as American ambassador to Japan.

As the US is set to commemorate the 50th anniversary of the JFK's death, Caroline Kennedy landed at Narita airport in the Japanese capital.

"I bring greetings from President Obama. He is a great admirer of Japan, and I am honoured to represent him as the United States Ambassador," Kennedy said upon arrival.

"I am also proud to carry forward my father's legacy of public service. He had hoped to be the first United States President to visit Japan.

"So it is a special honour for me to be able to work to strengthen the close ties between our two great countries," she said.

Kennedy, a 55-year-old lawyer was appointed as US envoy by Obama earlier this year and is seen as a close ally to the president.

She is the first woman to serve as US ambassador to Japan.

Kennedy played a pivotal role in securing support for Obama's Democratic presidential primaries victory against Hillary Clinton in 2008.

"What's important here is her strong pipeline with Obama and an ability to be able to pick up the phone and speak with Obama directly in the middle of the night for consultation on urgent matters," said Ryuichi Teshima, professor of diplomacy at Keio University in Tokyo.

Diplomatic relations between Washington and Tokyo are stable and friendly, but Kennedy will have to handle a few thorny issues such as local discontent towards US military presence in Okinawa and the planned relocation of the base.

"Japan and the United States share a commitment to freedom, democracy and the rule of law - and we work together on important global humanitarian efforts and civil society initiatives," Kennedy said. "Our Alliance is critical to a prosperous and peaceful world."

Relations personal relations between Obama and Japanese conservative Prime Minister Shinzo Abe might also be an issue.

"The chemistry is off, possibly because Obama does not support the right-wing views Abe holds," Teshima said.