Canadian Prime Minister Justin Trudeau has joined a growing list of public figures targeted by pranksters posing as climate activist Greta Thunberg.
Audio of Mr Trudeau speaking to an accomplice of pranksters Vladimir Kuznetsov and Alexey Stolyarov in January has been released by the pair.
The prime minister apparently fielded questions from the fake Ms Thunberg, on Nato, world peace and Donald Trump.
"This is not the first prank call of a world leader," his office said.
"The Prime Minister determined the call was fake and promptly ended it," Mr Trudeau's office said in a statement.
"Hello Greta!" the recording begins.
"I understand that you have a lot of work and not so much time to talk to a young girl, but I'm very concerned about the growing international crisis," the impersonator responds.
Days before the recording, Ukraine International Airlines flight PS752 had been shot down after taking off from the Iranian capital of Tehran, amid escalating tensions between Iran and the US. All passengers and crew on board the flight were killed, including 57 Canadian citizens.
Mr Trudeau told the fake Ms Thunberg that he had received "many many phone calls" on the subject talking about "de-escalation on all sides".
The fake Ms Thunberg then told Mr Trudeau that he and other world leaders "are adults, but you act like children".
"Leave Nato, drop your weapons, pick flowers, smile at nature," she said.
Taking the increasingly strange comments in stride, Mr Trudeau applauded the fake Ms Thunberg for her "perspective" and "passionate words".
Asked about US President Donald Trump - whom she described with an expletive - Mr Trudeau replied that his responsibility was to "work with world leaders that other people choose".
"I can certainly understand that people can feel very, very strongly about him," Mr Trudeau said.
Mr Kuznetsov and Mr Stolyarov have previously targeted Elton John, Prince Harry, and Vice-President-elect Kamala Harris for pranks.
Critics have accused the pair of being linked to Russian security services, which they deny.
"We only choose the subjects we are interested in ourselves," Mr Kuznetsov told the Guardian in 2016.