Julian Assange’s WikiLeaks operation has published a series of secret documents about the U.S. National Security Agency (NSA) bugging foreign leaders. It claims some of them are “the most highly classified documents ever published by a media organization.”

The documents, covered in news stories in a range of publications, show the NSA bugged a range of high-level conversations, including talks between German chancellor Angela Merkel and UN secretary-general Ban Ki-moon on the issue of climate change. The NSA also spied on the French and Italian premiers and their aides.

The WikiLeaks cache includes a series of redacted phone numbers for the bugging targets, that show up as so-called selectors. This generally denotes the search terms that intelligence analysts will use to find what they want in data that has been intercepted in bulk.

The issue of the NSA spying on Merkel is, of course, not new — in 2013’s flurry of revelations about the agency, it caused great outrage in Berlin and embarrassment in Washington.

“Today we showed that UN Secretary General Ban Ki-moon’s private meetings over how to save the planet from climate change were bugged by a country intent on protecting its largest oil companies,” said Assange. “The U.S. government has signed agreements with the UN that it will not engage in such conduct against the UN — let alone its secretary-general.”

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The spy agency also reported on 2010 conversations between Italian prime minister Silvio Berlusconi and Israeli prime minister Benjamin Netanyahu, on the subject of patching up Israel’s relationship with the U.S.

French prime minister Nicolas Sarkozy is shown in the documents to have pressured Berlusconi in 2011 over Italy’s finances, claiming that its banks could soon “pop” like a champagne cork. As l’Espresso notes, this revelation revisits questions around why Berlusconi had to step down that year.

WikiLeaks also noted that the documents show the NSA spied on the head of the UN refugee agency.