WIKILEAKS published evidence of the United States spying on its ally Japan yesterday, including a list of government and business targets.

The whistle-blowing website published its “Target Tokyo” list of 35 of US National Security Agency (NSA) targets — the Cabinet Office, the Bank of Japan and corporate giants Mitsubishi and Mitsui among them — going back at least eight years.

The latest release of leaked documents includes five NSA reports showing that Washington was keeping tabs on the Japanese cabinet’s discussions on climate change and trade policy.

While four of the reports are classified top secret, one is marked for sharing with Britain, Australia, Canada and New Zealand, the other members of the “Five Eyes” intelligence partnership.

Other documents show that the NSA was snooping on Japanese technical development plans, nuclear and energy policy — including correspondence with the International Energy Agency and others — and diplomatic relations strategy concerning the US and European Union.

WikiLeaks investigations editor Sarah Harrison asked: “Would the effectiveness of Japan’s industry and climate change proposals be different today if its communications had been protected?”

The WikiLeaks release follows earlier revelations that the US was spying on Nato allies France and Germany.

Japanese Prime Minister Shinzo Abe has, in recent weeks, tried to portray neighbouring China as a threat to national security to justify unpopular new legislation allowing the armed forces to be deployed overseas — in breach of the country’s post-war constitution.

But WikiLeaks editor-in-chief Julian Assange warned Japan to watch out for its ostensible ally the US.

“In these documents, we see the Japanese government worrying in private about how much or how little to tell the United States, in order to prevent it undermining its climate change proposal or its diplomatic relationship,” he said.

“And yet we now know that the United States heard everything and read everything and was passing around the deliberations of the Japanese leadership to Australia, Canada, New Zealand and the UK.”

Mr Assange said the lesson for Japan was: “Do not expect a global surveillance superpower to act with honour or respect. There is only one rule: there are no rules.”