Canadian Prime Minister Justin Trudeau sought the release of two Canadians held by China in talks with President Xi Jinping at the Group of 20 leaders summit where their frosty ties were on display.

Trudeau said he had constructive conversations with Xi on Saturday at the end of the gathering of world leaders in Osaka, Japan. He didn’t, however, mention any details about the dispute at the core of their recent tension -- Canada’s detention of Huawei Technologies Co.’s chief financial officer, who is facing charges in the U.S.

"We recognize that Canada and China are going through a challenging moment right now," Trudeau told a news conference. The tension between the two was evident when, due to assigned seating, they were perched next to each at a working lunch and avoided interacting.

The two later met, however, and Trudeau said he pressed the Chinese leader on the case of the Canadians.

After coming to power in 2015, Trudeau had put China at the center of his government’s trade diplomacy and even toyed with the idea of a free trade agreement -- pledging to double two-way trade in a decade. But those ambitions were walloped after the arrest of Huawei’s Meng Wanzhou in December.

The U.S. accuses Meng, who is under house arrest in Vancouver and awaiting extradition to the U.S., of tricking banks into conducting more than $100 million worth of transactions for Huawei that may have violated U.S. sanctions on Iran. China and Huawei have denied any wrongdoing.

Since then, Beijing has detained two Canadians, -- Michael Kovrig and Michael Spavor -- halted imports of canola and is now turning away meat shipments from Canada.

Meng was arrested on Dec. 1. China detained both Canadian citizens on Dec. 10. The two remain in Chinese custody and China has repeatedly defended its actions against the two it accuses of stealing state secrets.