The nomination Thursday of a virtually unknown lawyer as the next U.S. ambassador to Japan was greeted with more concern than optimism by experts and the government.

Chief Cabinet Secretary Takeo Kawamura welcomed the nomination of John Roos, calling it "proof that the Obama administration considers the Japan-U.S. alliance important."

Kawamura brushed off concern that Roos lacks diplomatic experience, saying there are specialists to support the ambassador, whoever he or she is. Instead, the top government spokesman said Japan is counting on the strong personal ties between Roos and President Barack Obama.