The National Security Agency whistleblower, Edward Snowden, has said that the mass surveillance programmes used by the US to tap into phone and internet connections around the world are making people less safe.

In short video clips posted by the WikiLeaks website on Friday, Snowden said that the NSA's mass surveillance, which he disclosed before fleeing to Russia, "puts us at risk of coming into conflict with our own government".

A US court has charged Snowden with violating the Espionage Act, for disclosing the programmes which he described as a "dragnet mass surveillance that puts entire populations under sort of an eye that sees everything even when it's not needed".

"They hurt our economy. They hurt our country. They limit our ability to speak and think and live and be creative, to have relationships and to associate freely," Snowden said.

The videos are the first of Snowden speaking since 12 July, when the former NSA analyst was shown at a Moscow airport, pleading with Russian authorities to grant him asylum, which they did on 1 August. That decision has strained relations between the US and Russia; President Barack Obama called off a meeting with President Vladimir Putin at a Russia-hosted summit in September.

Snowden said the US government was "unwilling to prosecute high officials who lied to Congress and the country on camera, but they'll stop at nothing to persecute someone who told them the truth".

In a note accompanying the videos, WikiLeaks said Snowden spoke on Wednesday in Moscow as he accepted the Sam Adams Award, named for a CIA analyst during the Vietnam War who accused the US military of deliberately underestimating the enemy's strength for political purposes, and given annually by a group of retired US national security officers.

Four former US government officials who were at the ceremony told the Associated Press on Thursday that Snowden is adjusting to life in Russia and said they saw no evidence that he was under the control of local security services. They refused to say where they met with Snowden or where he is living.