David Cameron's view on the powers of the UK intelligence agencies remains unchanged, his official spokesman has said, after a White House report recommended sweeping changes to the way US security services operate to stop widespread surveillance of American citizens.

As reaction flooded in from around the world, the prime minister's spokesman refused to comment on the report, which was commissioned by Barack Obama in the wake of the whistleblower Edward Snowden's revelations about the extent of spying by British and American agents.

However, he stressed that Cameron believed the UK already had a strong system of oversight for the intelligence services and praised their work in keeping the country safe.

On Wednesday the White House review panel found the National Security Agency should be banned from attempting to undermine the security of the internet and stripped of its power to collect telephone records in bulk.

The 300-page report by Obama's review group on intelligence and communications technology comes as the White House faces growing pressure over its so-called "bulk collection" programmes from US courts and business interests.

This week a federal judge ruled that the bulk collection programme, first revealed by the Guardian in June through a court order against Verizon, was likely to be in violation of the US constitution, describing it as "almost Orwellian" in scope.

Asked for his response to the US developments and how it might affect the work of the UK's GCHQ, Cameron's official spokesman said: "As I understand it, it's a report to the US administration and we don't comment about the exchanges that we have, the very close security relationship with the US. We don't comment on the details."

The White House report also suggested that the bulk collection of metadata was "not essential to preventing attacks".

Asked whether Cameron believed the storage of personal data of citizens was necessary to catch terrorists, the spokesman said: "Neither the PM nor anyone in the government has commented on the details of how our intelligence agencies operate."

He added: "The PM's view on all this is unchanged. The very important work that our agencies do is very important in keeping this country safe and the PM believes we should continue to support them with that. Alongside, we need a strong system of oversight and the PM believes we have that."

Cameron has repeatedly backed spy chiefs who have criticised the Guardian's publication of stories based on Snowden's leaks, suggesting it has undermined their work against terrorists.

However, he also broadened the scope of an inquiry by parliament's intelligence and security committee to examine the extent and scale of mass surveillance undertaken by Britain's spy agencies.

Nick Clegg, the Lib Dem deputy prime minister, has said he believes the case for a wider public inquiry into oversight of the security services is getting stronger.