Chief Cabinet Secretary Yoshihide Suga said that the nomination reflected the importance the US government attaches to its longtime ally. (Agencies)
"She is known to be very close to President Obama. As US ambassador, one of the most crucial questions is if or how he or she can communicate a variety of issues with the president. For that role I would give her a big welcome," Suga said.
The 55-year-old Kennedy is being awarded for helping put Obama in the White House, where her father, President John F Kennedy, served until his assassination 50 years ago.
If confirmed as ambassador to Japan, one of the United States' most important trading and military partners, she would be the first woman in the post, replacing John Roos, a wealthy former Silicon Valley lawyer and a top Obama campaign fundraiser.
Obama announced the nomination on Wednesday, offering the most famous living member of a prominent American family a new role of service to the country.
In a country that likes prestige and brand name, the family name Kennedy would be certainly well received."Many Japanese people feel close to the late President Kennedy," Suga said, adding that Japan's government is willing to support her.
Kennedy lacks any obvious ties to Japan, a key ally in dealing with North Korea's nuclear ambitions, and some experts have expressed concern that she might lack the capacity to handle thorny issues in the US-Japan relationship such as trade talks, tensions between Japan and China, and frictions over US military personnel based in Japan.
Suga shrugged such issues aside. Kennedy helped propel Obama to the 2008 Democratic presidential nomination in a celebrated endorsement over Hillary Rodham Clinton, the only time she's endorsed a presidential candidate other than her uncle Ted Kennedy in 1980.
She earned a bachelor's degree from Harvard University and a law degree from Columbia University. She married exhibit designer Edwin Schlossberg and had three children
Chief Cabinet Secretary Yoshihide Suga said that the nomination reflected the importance the US government attaches to its longtime ally.