A Chinese court on Monday sentenced a Canadian man to be executed for drug smuggling, prompting Canada's Prime Minister Justin Trudeau to accuse China of using the death penalty arbitrarily.

The ruling, and Trudeau's reaction could aggravate already sour relations between Beijing and Ottawa following the arrest of a senior Chinese executive in Canada and China's subsequent detention of two Canadians.

The Dalian Intermediate People's Court in China's northeast province of Liaoning re-tried Robert Lloyd Schellenberg, who had appealed his original 15-year prison sentence, and decided on execution, the court said in a statement.

Trudeau strongly condemned Monday's proceeding, suggesting that China was using its judicial system to pressure Canada over the arrest of Meng Wanzhou, chief financial officer of the Chinese telecommunications giant Huawei.

In his strongest comments yet, Trudeau said, "All countries around the world" should be concerned that Beijing is acting arbitrarily with its justice system.

"It is of extreme concern to us as a government, as it should be to all our international friends and allies, that China has chosen to begin to arbitrarily apply a death penalty," Trudeau said.

Canada later updated its travel advisory for China urging Canadians to "exercise a high degree of caution due to the risk of arbitrary enforcement of local laws."

10 days to appeal

Schellenberg was told in court he had the right to appeal to Liaoning High Court within 10 days upon receiving the ruling, the intermediate court said in a second statement.

Schellenberg's lawyer said on Monday he would appeal.

"It is of extreme concern to us as a government, as it should be to all our international friends and allies, that China has chosen to begin to arbitrarily apply (the) death penalty ... as in this case," Trudeau told reporters in Ottawa.

Schellenberg's aunt, Lauri Nelson-Jones, said the family's worst fears had been confirmed.

"Our thoughts are with Robert at this time. It is rather unimaginable what he must be feeling and thinking," she said in a statement to Reuters.

"It is a horrific, unfortunate, heartbreaking situation. We anxiously anticipate any news regarding an appeal."

TRT World speaks to Chris Alexander, a former Canadian diplomat in Russia.  

'Politicising law' 

China is not putting pressure on Canada by sentencing a Canadian to death for drug smuggling, and any suggestion it was doing so showed "rude contempt" of China's law, its state media said.

"Public opinion in Canada has claimed recently that China is 'politicizing' Schellenberg's case, but what Canada is doing is actually politicizing law," the Global Times said.

China-Canada ties turned icy in early December after Meng was arrested in Vancouver on a US extradition warrant.

China warned of unspecified consequences unless Meng was released, and detained Michael Kovrig, a Canadian diplomat on unpaid leave from the embassy in Beijing, and Michael Spavor, a Canadian consultant, on suspicion of endangering state security.

Beijing has not drawn a direct link between the detentions and the arrest of Meng, wanted by US authorities for allegedly misleading multinational banks about Iran-linked transactions. Western diplomats in Beijing, however, say the cases are a tit-for-tat reprisal.

Lu Shaye, China's ambassador to Canada, suggested in a newspaper article last week that the arrest of Kovrig and Spavor was "China's self-defence," but did not give details.

Earlier on Monday, China's government dismissed Trudeau's statement that Kovrig enjoyed some form of diplomatic immunity.

A Chinese foreign ministry spokeswoman said Trudeau should "earnestly study" the Vienna Convention governing diplomatic ties so as to "not become a laughing stock."

Trudeau said Ottawa "will continue to engage strongly" with Beijing over Kovrig's status and what he called China's arbitrary use of justice.

Rights groups condemned the Schellenberg sentence while Guy St-Jacques, who was Canada's ambassador in Beijing when Kovrig worked there, expressed concern at how quickly the courts had acted.

"The Canadian government will make representations in Beijing, but based on past experience I am not sure whether this will work," he told the CBC. "We are in a very difficult place."

222 kilogrammes of methamphetamine

St-Jacques said Canada should immediately call for a top-level meeting of foreign policy and security advisers from the two nations "to impress upon the Chinese side that they have to abide by international law".

Alex Lawrence, chief spokesman for Canadian Foreign Minister Chrystia Freeland, declined to comment.

William Nee of Amnesty International noted that drug-related offences did not meet the threshold of the "most serious crimes" to which the death penalty must be restricted under international law.

Drug smuggling is routinely punished severely in China. Beijing has previously executed foreign nationals convicted of drug-related crimes - a Briton was executed in 2009.

The court said Schellenberg had conspired with others in an attempt to smuggle 222 kg (489.43 lb) of methamphetamine from China to Australia in late 2014.

Chinese state television said in an earlier report that Schellenberg argued in court that he was a tourist visiting China and was framed by criminals.

A lawyer for Schellenberg, Zhang Dongshuo, told Reuters his client would probably appeal against the death sentence.

The Liaoning High Court in late December ordered the case retried after prosecutors said the sentence was too light and improper.

Beijing considers the number of people executed in China to be a state secret. International human rights organisations estimate the annual figure at around 2,000.