NEW YORK (Reuters) – Germany’s U.N. envoy, during his last scheduled U.N. Security Council meeting, appealed to China to free two detained Canadians for Christmas, prompting China’s deputy U.N. envoy to respond: “Out of the bottom of my heart: Good riddance.”

Germany finishes a two-year term on the 15-member council at the end of this month and Ambassador Christoph Heusgen plans to retire after more than 40 years as a diplomat.

“Let me end my tenure on the Security Council by appealing to my Chinese colleagues to ask Beijing for the release of Michael Kovrig and Michael Spavor. Christmas is the right moment for such a gesture,” Heusgen told the council session, whose official agenda topic was Iran.

Kovrig, a former Canadian diplomat who was working as an adviser for the International Crisis Group think tank, and businessman Spavor were detained by Beijing in 2018 shortly after Canadian police picked up Huawei Technologies Co Ltd Chief Financial Officer Meng Wanzhou on a U.S. warrant.

China’s deputy U.N. ambassador, Geng Shuang, accused Heusgen of abusing the Security Council to launch “malicious” attacks on other members “in an attempt to poison the working atmosphere”.

“I wish to say something out of the bottom of my heart: Good riddance, Ambassador Heusgen,” Geng said. “I am hoping that the council in your absence in the year 2021 will be in a better position to fulfil the responsibilities…for maintaining international peace and security.”

Heusgen also used the Security Council meeting to advise Russia’s deputy U.N. ambassador, Dmitry Polyanskiy, to read certain articles about Russian opposition politician Alexei Navalny, who said he had tricked a Russian secret agent into disclosing details of a botched plot to kill him. Russia’s FSB security service dismissed the recording as a fake.

Polyanskiy replied: “It seems he’s developed a certain dependency on the council, there’s never a meeting without criticism of Russia even if that’s not suitable for the subject matter. I hope that after Jan. 1 that Christoph’s symptoms will improve.”