Trump Offers Canada Support Over Mainland Arrests

US President Donald Trump spoke to Canadian Prime Minister Justin Trudeau overnight on Thursday and offered his support for Canadian citizens detained in China, the White House said.

Four Canadians, including a Hong Kong-based former diplomat, have been detained on the mainland, two of whom have been sentenced to death over drug smuggling accusations.

"During the call, the President expressed the United States' solid commitment to standing by Canada in efforts to secure the fair treatment and release of Canadian citizens currently detained in China," the White House said.

The two leaders also discussed trade negotiations with China and the new North American free trade pact, the statement said.

A Chinese court adjourned a hearing on Thursday on Canadian Robert Lloyd Schellenberg's appeal against his sentence for drug smuggling.

He was sentenced to death in January after a court deemed his previous 15-year prison sentence too lenient.

Trudeau has said that China had "chosen to arbitrarily" sentence Schellenberg to death. His government has pleaded for clemency.

Schellenberg's case is seen as potential leverage for Meng Wanzhou, a top executive at tech giant Huawei, who was arrested in Canada on a US extradition request related to Iran's sanctions violations.

Following her arrest in December, the mainland authorities detained former Canadian diplomat Michael Kovrig and businessman Michael Spavor, in what observers saw as retaliation.

They have been denied access to lawyers and are allowed only monthly consular visits. (AFP)