General Keith Alexander, the then director of the NSA, was briefed that the Guardian was prepared to make a largely symbolic act of destroying documents from Edward Snowden last July, new documents reveal.

The revelation that Alexander and Obama's director of national intelligence, James Clapper, were advised on the Guardian's destruction of several hard disks and laptops contrasts markedly with public White House statements that distanced the US from the decision.

White House and NSA emails obtained by Associated Press under freedom of information legislation demonstrate how pleased Alexander and his colleagues were with the developments. At times the correspondence takes a celebratory tone, with one official describing the anticipated destruction as "good news".

On 20 July 2013, three Guardian editors destroyed all copies of the its Snowden material held in London (video), under the supervision of two GCHQ staff following a period of intense political pressure in the UK.

The decision to destroy the UK copies of the material was taken in a climate of advancing legal threats from Cabinet Office and intelligence officials. The Guardian and its publishing partners, which included the New York Times and the not-for-profit news organisation ProPublica, held other copies of the material in the US, and continued reporting revelations from the documents.

When the Guardian revealed it had destroyed several computers a month later in August, the White House spokesman Josh Earnest initially remarked it was hard to "evaluate the propriety of what they did based on incomplete knowledge of what happened" but said it would be hard to imagine the same events occurring in the US.

"That's very difficult to imagine a scenario in which that would be appropriate," he concluded.

However, heavily redacted email correspondence obtained by AP reporter Jack Gillum shows senior NSA officials celebrating the destruction of the material, even before it had occurred.

An email to Alexander from Rick Ledgett, now deputy director of the NSA, has the subject line "Guardian data being destroyed", and is dated 19 July, a day before the destruction of the files. Most is heavily redacted, but Ledgett remarks: "Good news, at least on this front."

A day later, hours after the material was destroyed, Alexander follows up with Ledgett, asking: "Can you confirm this actually occurred?"

Later that day, Clapper emails Alexander under the same subject line, saying: "Thanks Keith … appreciate the conversation today".

The remainder of the emails are redacted, including the subject lines in many cases, meaning it is unclear who from the British government briefed the senior NSA and White House staff on the destruction, or whether US officials had any input to the decision to encourage destruction of journalistic material.

A spokeswoman for the Guardian said the revelation of the US-UK correspondence on the destruction was disappointing.

"We're disappointed to learn that cross-Atlantic conversations were taking place at the very highest levels of government ahead of the bizarre destruction of journalistic material that took place in the Guardian's basement last July," she said. "What's perhaps most concerning is that the disclosure of these emails appears to contradict the White House's comments about these events last year, when they questioned the appropriateness of the UK government's intervention."

The NSA and GCHQ declined to respond to AP's requests for comment on the email exchange.