Al Jazeera reports Japan has described claims that the US spied on Japanese politicians and major firms as "deeply regrettable", in its first official response to revelations by the whistleblower group WikiLeaks. The latest WikiLeaks intercepts exposing US National Security Agency (NSA) activities follow other documents that revealed spying on allies including Germany and France, straining relations. "I will withhold comment. But If this is true, as an ally, it's deeply regrettable," Yoshihide Suga, the government's top spokesperson, said on Monday. He said Japan was checking with the US on the Wikileaks report issued on Friday. Japan is one of the key allies of the US in the Asia-Pacific region and the two countries regularly consult on defense, economic and trade issues.