On Friday, WikiLeaks published a series of secret NSA documents detailing US eavesdropping on 35 targets in Japan, including high-ranking officials.
"If that (interception) is true, it is extremely regrettable for the allied countries," Suga, who was among the NSA’s targets, said, Sputnik reports on Monday.
The NSA telephone interception target list included the Japanese Cabinet Office members, the Central Bank as well as the finance and economy ministries, Mitsubishi’s natural gas division and the Mitsui conglomerate’s petroleum division.
Japan is the latest NSA’s spying target among the US allies, uncovered by WikiLeaks. The revelation followed recently published documents unveiling the agency's eavesdropping practices on French, Saudi and German high-ranking officials.