Egypt is a key ally for the US and NATO in Mideast and receives around $1 billion in economic aid every year. (Reuters Archive)

The United States has said there is no evidence to suggest that Egypt is supplying Russia with lethal weapons after a leaked American document claimed Cairo secretly planned to supply rockets to Moscow.

"We've seen no indication that Egypt is providing lethal weaponry and capabilities to Russia," National Security Council spokesperson John Kirby told reporters on Tuesday.

"Egypt is a significant security partner and remains so."

Kirby said the Biden administration wants to obtain answers as soon as possible to identify where the breach took place. The US is investigating the leak of highly sensitive material posted online.

The Washington Post reported that one of the documents said Egypt's President Abdel Fattah el Sisi ordered the production of 40,000 rockets for shipment to Russia, telling officials to keep it secret to "avoid problems with the West."

The Post said it obtained the document "from a trove of images of classified files posted in February and March on Discord, a chat app popular with gamers."

A senior Egyptian official called the Post's report "informational absurdity."

The official told the state-run channel Al Qahera News TV that the plan to provide rockets to Russia was false, according to several Egyptian news outlets.

Most damaging release since WikiLeaks

The Pentagon said on Friday it was investigating the unauthorised disclosure of the documents, which carry US Joint Chiefs of Staff seals and allegedly belong to the US and NATO.

They were shared on social media, including Twitter and Telegram.

The Justice Department separately opened a criminal investigation into the leak.

The Biden administration has repeatedly declined to weigh in on their authenticity, but they include information about the war in Ukraine, humanitarian aid provided by different countries and calendars for aid being delivered to Kiev's forces.

Investigators are working to determine what person or group might have had the ability and motivation to release the intelligence reports.

The leaks could be the most damaging release of US government information since the 2013 publication of thousands of documents on WikiLeaks.

Some of the most sensitive information is purportedly related to Ukraine's military capabilities and shortcomings and one document mentions the small number of Western special forces troops in the country.

Some national security experts and US officials say they suspect that the leaker could be American, given the breadth of topics covered by the documents. More theories could develop as the investigation progresses, they said.

TRT World