China said that Canada should respect its sovereignty. "The comments coming from Canada lacks the most basic understanding of that, and we express our strong dissatisfaction", said Foreign Ministry spokesman Hua Chunying on Tuesday (Jan 15) at a regular press briefing.
The latest war of words will no doubt aggravate already strained diplomatic ties between the two sides after Canada arrested Huawei chief financial officer Meng Wanzhou last month on a United States extradition warrant, and China in turn detained two Canadians in what was seen as a retaliatory move.
The U.S. wants Meng extradited to face charges that she committed fraud by misleading banks about the company's business dealings in Iran.
Schellenberg, who has been detained since 2014, originally received a sentence of 15 years in a ruling in November last year.
An editorial in the nationalist state-backed Chinese newspaper Global Timeson Tuesday said "unreasonable speculation" in Western media linking his case to Ms Meng's showed "rude contempt toward Chinese law".
And despite the Canadian's insistence that he is innocent, his retrial lasted just a day, with his death sentence being announced barely an hour after its conclusion, our correspondent says.
He said his client now has 10 days to appeal.
The verdict has raised questions about whether Beijing is using the case to exert pressure on Ottawa after Canadian authorities detained senior Huawei executive, Meng Wanzhou, in December. Zhang said while the court's actions were all lawful, they were also "abnormal".
Schellenberg, who has previous drugs-related convictions in Canada, has denied the charges against him, saying he entered China as a tourist and was framed.
Descarta López Obrador asistir al foro económico mundial
Es el principal evento anual del Foro Económico Mundial , comúnmente llamado Foro de Davos , debido al lugar donde se organiza (la ciudad Suiza de Davos ).
"It is of extreme concern to us as a government, as it should be to all our global friends and allies, that China has chosen to begin to arbitrarily apply [the] death penalty ... as in this case facing a Canadian", Trudeau said.
Responding to Canada's decision to update a travel advisory to warn citizens about the "risk of arbitrary enforcement of local laws" in China, Hua said: "Canada should remind its own citizens to definitely not engage in drug smuggling in China".
A judge in Dalian, a coastal city, determined Schellenberg played a "key part" in a plan to send 222 kilogrammes of methamphetamine to Australia.
A Chinese man convicted of involvement in the same operation was earlier given a suspended death sentence.
She also disputed arguments from critics that the Chinese court had political motivation in imposing a severe sentence against Mr. Schellenberg.
"The sudden retrial and apparent rush to judgment has highlighted the numerous flaws in China's judicial system", China researcher William Nee said in a statement.
China is known for handing out harsh sentences for drug crimes including the death penalty when substantial amounts of illicit substances are involved.
In a move observers see as retaliation over the Huawei case, Chinese authorities detained two other Canadian citizens - a former diplomat and a business consultant - on suspicion of endangering national security.
"The Chinese government, in choosing to escalate this stand-off, is showing that it's immune - or simply doesn't care - about the damage it is doing to its reputation, so long as it somehow helps to get Mrs Meng back to China", he said.