"I hope that stepping away from the Paris accord will not have any negative impact with our relationship with the Ukraine," Perry said. "We tried to divorce the politics from this and really just let our record stand, one that I'm very proud of."
He also talked about a meeting scheduled for August where they'd let American business executives talk about extracting oil natural gas in Ukraine.
"What we have seen in Texas is the great increase of productivity, particularly in shale gas because of hydraulic fracturing and the directional drilling," Perry said.
Perhaps the only giveaway about the true nature of the call was a statement the "Ukrainian prime minister" made about a new biofuel invented by Ukrainian President Petro Poroshenko, according to the Pravda Report newspaper.
The fuel was made from a mix of home-brewed alcohol and pig manure.
Perry said he'd like to get more information about the "scientific development".
The pranksters seemed to get past Perry's defences with opportunistic timing.
On June 20, Perry hosted Groysman and his delegation at the Department of Energy, a meeting that was widely reported in the Ukrainian press, according to the DOE.
Three weeks later, the department received a request for a phone follow-up with the Ukrainian prime minster, in advance of another meeting with the Ukrainians in August.
That phone call happened on July 19.
The pranksters say they have a victims' list that includes several high-profile names: Elton John, Turkish President Recep Tayyip Erdogan, the Croatian prime minister, Nato Secretary-General Jens Stoltenberg, Congresswoman Maxine Waters and Senator John McCain. The rumour debunking website Snopes has said some of those claims are unproven, and points out that if the pranksters can impersonate one person on the phone, they can easily impersonate two.
The pranksters called singer Elton John in 2015 claiming to be Russian President Vladimir Putin. The call happened shortly after the singer had criticised the President's stance on LGBT rights.
"We thought it wasn't likely that Putin would want to meet with him and call, at least not so quickly," Krasnov said, according to the Guardian.
"But it turned out that Elton John was really waiting for this call, and so he immediately believed it really was a conversation with the people who we said we were," he told newspaper Komsomolskaya Pravda.
Elton John was elated about the call with the Russian leader. He posted "an effusive Instagram post in which he thanks the Russian leader for having reached out to him".
He took it down shortly afterward.
