The United States said Monday its intelligence activities are aimed at meeting its national security needs as well as those of its allies and partners after allegations surfaced that it spied on Japanese officials and firms.

The whistleblower Wikileaks on Friday disclosed what it claimed was a National Security Agency list of 35 Japanese targets of wiretapping, including the Japanese Cabinet office, Bank of Japan officials, the Finance and Trade Ministry as well as such companies as Mitsubishi and Mitsui.

Japanese Chief Cabinet Secretary Yoshihide Suga said the allegations, if true, would be "deeply regrettable."

The allegations have added to an embarrassment to the U.S. after WikiLeaks disclosed similar documents in recent weeks alleging that the U.S. spied on Germany, France and Brazil.

On Monday, State Department deputy spokesperson Mark Toner declined to confirm the allegations involving Japan, but said the two countries are in talks about the issue.

"We have been in touch with the Japanese government. I'm not going to talk about the contents of those discussions, but we are in touch," he said at a regular press briefing.

"Our intelligence activities are always focused on our national security needs as well as the needs of those allies and partners and I would just reiterate the fact that Japan is a stalwart U.S. partner and ally in the region," he said. (Yonhap)