Russian ambassador to the UK Andrey Kelin has condemned a note sent by London to the Kremlin regarding two British nationals recently sentenced to death by a Donetsk People’s Republic court. The “arrogant” message makes the Kremlin’s cooperation unlikely, Kelin added.

Sean Pinner and Aiden Aslin, as well as a Moroccan man, were sentenced to death by authorities in the Donetsk People’s Republic (DPR) earlier this month. The three had been captured by the DPR while fighting for Ukraine and were convicted of terror offences and of attempting to overthrow the government of the republic.

Both Russia and the DPR insist that the men were fighting as mercenaries and are therefore not lawful combatants. Pinner and Aslin claim they were active members of the Ukrainian military.

Speaking to the Rossiya 24 TV channel on Tuesday, Kelin confirmed that UK officials have been in touch with the Kremlin about the two British combatants. 

“They sent a note written in extremely arrogant, instructive terms. It does not make us want to cooperate on these issues,” Kelin stated.

Britain does not recognize the independence of the DPR, hence the note being sent to Moscow. British Foreign Secretary Liz Truss has called Pinner and Aslin’s conviction a “sham judgment with absolutely no legitimacy,” and in her official response to the sentence referred to the DPR authorities as “Russian proxies in eastern Ukraine.”

Moscow has previously told London to communicate directly with the DPR, instead of “trying to solve problems with loud statements,” according to Foreign Ministry spokeswoman Maria Zakharova.

Along with the Lugansk People’s Republic (LPR), the DPR declared independence from Ukraine in 2014. Russia recognized the two republics’ independence in February, days before launching its military operation in Ukraine, which the Kremlin insists was necessary to put an end to Kiev’s eight-year legal, cultural and military persecution of the two breakaway states.

Under DPR law, Aslin and Pinner may appeal their death sentence or plead for clemency. Should they fail in either endeavor, they will be executed by firing squad.