WASHINGTON (AFP) - Ms Caroline Kennedy said on Thursday that she hoped to carry on the legacy of her slain father John F. Kennedy as she pledged to seek deeper ties as ambassador to Japan.

Ms Kennedy, a close and early supporter of United States President Barack Obama, appeared before a Senate panel as she sought confirmation for her most public role since she was first daughter from 1961-1963.

"I can think of no country in which I would rather serve than Japan," said Ms Kennedy, with two of her three children and other members of the political dynasty sitting behind her.

The 55-year-old said that she first visited Japan in 1978 with her uncle, late senator Ted Kennedy, and was "deeply affected by our visit to Hiroshima", which the United States obliterated in the world's first atomic bombing in 1945.

Ms Kennedy said the two nations' alliance had a "global reach", calling Japan "an indispensable partner in promoting democracy and economic development".

"These are areas I care deeply about and, if confirmed, I will work to further strengthen this critical partnership at a vital moment in its history," she said.

The Senate appeared likely to confirm Ms Kennedy, meaning that she would head to Tokyo in time for the 50th anniversary of her father's assassination, when she was five days short of her sixth birthday.

"This appointment has a special significance as we commemorate the 50th anniversary of my father's presidency," she said.

"I would be humbled to carry forward his legacy in a small way and represent the powerful bonds that unite our two democratic societies," she said.

Senator Chuck Schumer, introducing Ms Kennedy to the Senate Foreign Relations Committee, said he believed her father and other late family members were "looking down with pride" on her.

Ms Kennedy, whose mother and brother have also died, has championed the family's brand of progressive politics but has mostly avoided the public spotlight.

But she offered a major boost to Mr Obama's presidential campaign when she urged voters from their Democratic Party to support him over perceived front-runner Hillary Clinton.

If confirmed, Ms Kennedy would join a long line of prominent ambassadors to Japan including former vice-president Walter Mondale, former House speaker Tom Foley and former Senate majority leader Howard Baker.

Japan has publicly praised her appointment, noting her ties to Mr Obama.

Mr Kenichiro Sasae, the Japanese Ambassador to the United States, took the rare step of personally attending the Senate confirmation hearing.

However, several US foreign policy experts have criticised the appointment, saying that she has little experience at a time that Japan is managing high tensions with a rising China and an often-bellicose North Korea.