The meeting was held between the Ministry of Defence and the US embassy’s top official.
“The defence ministry held a meeting with the US embassy in Oslo today where we made it clear that spying on allies is unacceptable and unnecessary,” Norway’s Defence Minister Frank Bakke-Jensen said on Twitter.
The ministry said the US charge d’affaires — Richard Riley, according to the embassy’s website — was the person who attended the meeting with a senior Norwegian official.
The US embassy is currently without an ambassador.
In an investigative report on Sunday, Danish public broadcaster DR revealed together with several other European media outlets that the US National Security Agency (NSA) had eavesdropped on Danish underwater internet cables from 2012 to 2014 to spy on top politicians in Germany, Sweden, Norway and France
The NSA was able to access text messages, telephone calls and internet traffic including searches, chats and messaging services — including those of Germany’s Chancellor Angela Merkel, then-foreign minister Frank-Walter Steinmeier and then-opposition leader Peer Steinbrück, DR said.
READ MORE: Europe demands answers after US-Danish spying claims
“I’m pleased that the Americans clearly said that they changed their practices in 2014 when it comes to the monitoring of allies, and that they want to cooperate with us and others to chart what happened,” Norwegian news agency NTB quoted Norwegian Prime Minister Erna Solberg as saying.
“We summoned the US embassy in Oslo today to follow up on this,” she added.
According to NTB, Solberg also held talks on Thursday with her Danish counterpart Mette Frederiksen.
“I reiterated that we consider espionage against close friends and allies unacceptable and unnecessary,” she said.
US eavesdropping on European leaders is, however, not new.
In 2013, former NSA contractor Edward Snowden revealed thousands of classified documents exposing the vast US surveillance put in place after the September 11th, 2001 attacks.
Among other things, the documents showed the US government was spying on its own citizens and carrying out widespread tapping worldwide, including of Merkel’s mobile phone.
However, if the Danish-US spying is confirmed, it went on during and after the 2013 Snowden affair.
In 2014, following the Snowden scandal, a secret internal working group at FE began looking into whether the NSA had used a Danish-US spying collaboration — called XKeyscore — to spy on Denmark’s allies, DR said.