The United States is trying to assess the risks associated with the leak of classified documents, including the Russian invasion of Ukraine, for its national security, said Sunday, April 9, the Pentagon. And seek to know the origin of the leaks.

The variety of topics covered in the documents – relating to the war in Ukraine, China, the Middle East, Africa – suggests that they were leaked by an American.

"The focus is now on the fact that this is a U.S. leak, as many of the documents were only in U.S. hands," Michael Mulroy, a former senior Pentagon official, told Reuters.

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According to U.S. officials, the investigation is still in its early stages and those leading it do not rule out the possibility that pro-Russian elements were behind the leak, considered one of the most serious security breaches since the WikiLeaks affair in 2013.

The Russian embassy in Washington and the Kremlin did not respond to requests for comment.

Documents likely to be modified

After the leak was leaked, Reuters reviewed more than 50 documents marked "Secret" and "Top Secret" that first appeared last month on sites like Discord and 4Chan. Some documents were published weeks ago, but their existence was first reported Friday by The New York Times.

Some estimates of casualties on Ukraine's battlefields appear to have been modified to minimize Russian casualties.

For unknown reasons, a document containing confidential information is marked as "unclassified".

Some documents are marked "NOFORN", which means that they cannot be communicated to foreign nationals.

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Two U.S. officials told Reuters on Sunday that the documents may have been altered to mislead investigators about their origin or spread false information that could harm U.S. interests.

One of the documents, dated Feb. 23 and marked "Secret," details how Ukraine's S-300 air defense systems could, at the current rate of use, be depleted by May 2.

The information could be of great help to Russian forces, and Ukraine said its president and senior security officials met Friday to discuss ways to prevent leaks.

Israel spied on by Washington?

Another document marked "Top Secret" indicates that Israel's Mossad intelligence agency has encouraged protests against Israeli Prime Minister Benjamin Netanyahu's justice reform plan, which would allow the government to have greater weight over the Supreme Court.

The document states that the United States learned of this through its intelligence services, implying that the Americans may have been spying on one of its main allies in the Middle East.

In a statement issued Sunday, Benjamin Netanyahu's office denounced the information as "false and without any foundation".

Another document details discussions among senior South Korean officials about U.S. pressure on Seoul to supply weapons to Ukraine. A South Korean presidential official said Sunday that the country was aware of the reports and planned to discuss the "issues raised" with Washington.

Two U.S. officials, speaking on condition of anonymity, said there were concerns about the leaks but the documents related to material more than a month old.

The Pentagon reiterated Sunday that it was reviewing the situation and had formally asked the Justice Department to investigate the incident. The latter said he was in contact with the Ministry of Defense and had opened an investigation into the leak, without further comment.

"Interagency cooperation has been launched to assess the impact that (the leak of) these photographed documents could have on national security and on our allies and partners," Pentagon spokeswoman Sabrina Singh said.

An official told Reuters investigators were considering four or five hypotheses, ranging from a disgruntled employee to an insider threat wanting to harm U.S. national security interests.

With Reuters and AFP

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