Trudeau tweeted: "Earlier tonight, the aircraft carrying Michael Kovrig and Michael Spavor left Chinese airspace. After an unbelievably difficult ordeal, they are on their way home. I want to thank every single person and partner around the world who helped secure their release."

The Canadians were identified as Michael Spavor and Michael Kovrig.

The two nationals were accused of espionage in 2018.

They were accused after the Canadian police arrested a top Chinese tech executive on a US warrant.

Huawei executive Meng Wanzhou left Canada after a deal was reached with US prosecutors.

The detention of the Canadian nationals had triggered diplomatic tension between two nations.

Reacting to the development, US Secretary of State Antony Blinken said: "The U.S. Government stands with the international community in welcoming the decision by People’s Republic of China authorities to release Canadian citizens Michael Spavor and Michael Kovrig after more than two-and-a-half years of arbitrary detention."

"We are pleased that they are returning home to Canada," he said.