The finishing touches are being applied to the long-anticipated formal announcement that Caroline Kennedy will be the next U.S. ambassador to Japan.

Caroline Kennedy with Irish Prime Minister Enda Kenny during a ceremony to unveil a bust of her uncle, the late senator Edward Kennedy, at the former home of the Kennedy family in County Wexford, Ireland, last month. (Niall Carson/AP)

Word is that the administration has formally asked — and Japan is expected to agree — to accept her as the U.S. envoy — a move that comes in the last stages of  the lengthy nomination process.

Kennedy's strong support for President Obama was seen as crucial in his 2008 battle with Hillary Rodham Clinton for the Democratic presidential nomination.

An official White House announcement, which is probably forthcoming shortly, is expected to thrill the Japanese public, which likes their American ambassadors to be superstars — although older men have been the norm. Kennedy's predecessors include luminaries such as Senate majority leader Mike Mansfield, former vice president Walter Mondale, former House speaker Tom Foley and former Senate majority leader Howard Baker.

Word of this latest step was first reported late Friday by the Nelson Report and then this morning by the Japanese press.

Correction: An earlier version of this post incorrectly said that Japan has given its formal diplomatic agreement to accept Caroline Kennedy as the U.S. envoy. It is expected to agree but has not yet done so.