"As far as we know, no such thing has taken place, but it is impossible for me to guarantee it in any way," Anders Anundsen said after being asked in parliament about American surveillance of Norwegian citizens. "It is difficult for us to get into a position where we can know what other powers are engaged in".
On Tuesday, Norway's Dagbladet newspaper published documents it claimed showed that the NSA logged 33m pieces of information on phone calls made by Norwegians over just one month.
However, Kjell Grandhagen, the chief of Norway's military intelligence service, said that the newspaper had misinterpreted the documents, and that the calls were made abroad and monitored by his agency as part of the fight against "international terrorism".
Glenn Greenwald, the American journalist who has disseminated leaks from NSA-contractor Edward Snowden, defended the Dagbladet article, which he co-wrote, arguing that it was clear that the documents referred to data collected in Norway, and not simply by Norwegian intelligence services.
"The NSA's own documents say this shows collection AGAINST the named country," he wrote on Twitter, promising "more reporting and more docs coming in Norway and very soon".