The United States' National Security Agency (NSA) spied on meetings between world leaders, according to the latest documents released by Wikileaks on Tuesday.
UN Secretary General Ban Ki-Moon, German Chancellor Angela Merkel, Israeli Prime Minister Benjamin Netanyahu and former Italian Prime Minister Silvio Berlusconi are among the leaders mentioned in the documents.
One notable document relates to a conversation between Netanyahu and Berlusconi.
The Israeli prime minister reportedly "begged Berlusconi" to help him repair relations with the United States and help him deal with Barack Obama.
Last year, relations between Obama and Netanyahu - and Israel and the US more generally - suffered over the agreement of the nuclear deal between the world powers led by the US under Obama and Iran.
The document also reveals that the NSA spied on a meeting between Ban Ki-Moon and Angela Merkel in which they discussed climate change.
— WikiLeaks (@wikileaks) February 23, 2016
Julian Assange, the founder of Wikileaks who took refuge at Ecuador’s embassy in London to avoid extradition to Sweden, said some of the documents are classified TOP-SECRET/COMINT-GAMMA and are the most highly classified documents ever published by his organisation.
"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.
"We previously published Hillary Clinton's orders that US diplomats were to steal the Secretary General's DNA. The US government has signed agreements with the UN that it will not engage in such conduct against the UN - let alone its Secretary General," he said.
"It will be interesting to see the UN's reaction, because if the Secretary General can be targeted without consequence then everyone from world leader to street sweeper is at risk."
Former NSA contractor Edward Snowden released documents in 2013 accusing the US spy agency of listening in on German Chancellor Angela Merkel’s conversations.
However, German prosecutors did not purse a legal suite against the US, saying there was not enough evidence to do so.