WikiLeaks published a new set of documents Tuesday claiming that the United States National Security Agency (NSA) spied on meetings between world leaders, including the United Nations Secretary General Ban Ki-Moon, German Chancellor Angela Merkel and Israel Prime Minister Benjamin Netanyahu. WikiLeaks said in a statement released Tuesday that the documents were classified as “Top Secret” and were the most highly classified documents ever to be published by a media organization.

The document said that the meeting between Merkel and Ban was about climate change, over which an accord was signed by nearly 200 countries in December agreeing to reduce greenhouse emissions to keep the effects of global warming at bay. The document claims that the NSA spied on the meeting with a motive of protecting the largest oil companies.

"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. We previously published Hillary Clinton orders that U.S. diplomats were to steal the Secretary General's DNA,” Julian Assange, WikiLeaks’ editor said in the statement.

The document also revealed that U.S. officials tapped a meeting in 2010 between Netanyahu and former Italian Prime Minister Silvio Berlusconi, where the former asked for the Italian leader’s help to deal with U.S. President Barack Obama. The documents also mentioned another meeting between Berlusconi and former French President Nicolas Sarkozy during which the former admitted that the Italian banking system was due to “pop like a cork.”

The documents further said that a private meeting between Berlusconi, Merkel and Sarkozy was tapped by the NSA, which has been embroiled in controversy since it was revealed by former U.S. spy agency contractor Edward Snowden that the organization spied on many world leaders and collected phone records of several Americans. In June last year, the Congress passed a law that ended keeping such records on phone calls of American citizens and it was put in place in November.

Assange also said in the statement: “The U.S. government has signed agreements with the U.N. that it will not engage in such conduct against the U.N. — let alone its Secretary General. It will be interesting to see the U.N.'s reaction, because if the Secretary General can be targeted without consequence then everyone from world leader to street sweeper is at risk.”

Another meeting between leaders from the European Union and Japanese trade ministers to discuss the final compromises made potentially toward the World Trade Organization negotiations, was also tapped, the statement by WikiLeaks said.

WikiLeaks was founded in 2006 in Iceland and aims to “disseminate documents, photos and video of political or social significance,” the organization’s Facebook page says. In 2010, WikiLeaks had released over 90,000 secret documents on the U.S.-led military campaign in Afghanistan, followed by about 40,000 military documents of the U.S. military, detailing its operations in Iraq. The Iraq disclosures were followed by millions of diplomatic cables, dating back to 1973, being released.

In June 2012, Assange took refuge at Ecuador’s London embassy to avoid being extradited to Sweden. He is wanted there for questioning over allegations of a sexual assault in 2010, an accusation he denies.