Yang warned the US to stop meddling in China's "internal affairs" and said it should "stop advancing its own democracy in the rest of the world," adding that many Americans "actually have little confidence in the democracy of the United States."

His remarks went far beyond the two minutes US officials said they had agreed upon before the talks, and Blinken insisted on issuing a rebuttal while the media was still present, with the Chinese then accusing him of being "condescending," as their US counterparts complained of "grandstanding."

Exchanges behind closed-doors appear to have been more congenial, however. A senior White House official told reporters after the first session finished that talks were "substantive, serious, and direct."

"We used the session, just as we had planned, to outline our interests and priorities, and we heard the same from our Chinese counterparts," they said, before the second set of talks began.

That meeting is expected to stretch into the late Alaskan evening, with the final set of talks due to begin Friday morning local time.

'Biggest geopolitical test'

Since before Biden was elected last year, Beijing has made clear that while it desires a reset of relations with Washington, it wants one on its own terms.

Beijing may have been hoping for a relationship more like that it enjoyed during Biden's last stint in government, under President Barack Obama, whose rhetoric about being tough with China and a supposed "pivot to Asia" did not have much effect on the two countries' economic ties, nor according to critics, do much to restrain Chinese territorial ambitions.

Blinken, for his part, has made it clear that this is not on the cards. He has called the US-China relationship "the biggest geopolitical test of the 21st century," and ahead of the Alaska meeting this week, rallied Washington's allies in the region against Beijing.

Spavor's trial began on Friday in Dandong, China, as officials were meeting in Alaska. Previously both Blinken and Biden have urged Beijing to release the two men, whose detention Ottawa and Washington regard as arbitrary and political, and doing so -- potentially after a face-saving conviction and sentence of time-served -- could be an easy sign of good will from Beijing.

According to Chinese state media and Canadian officials at the scene, Spavor's trial wrapped up in a matter of hours. A statement on the website of Liaoning Dandong Intermediate People's Court said that a verdict would be announced "at a later date in accordance with the law." Kovrig's trial is expected to begin Monday.

United front

Such good will could be in short supply however, depending on how high hopes were from Beijing going into the Alaska summit.

His Japanese counterpart, Toshimitsu Motegi, said the "free and open international order is greatly challenged by attempts to change the status quo by force and progress of authoritarian system," and added Tokyo and Washington agreed on the need to hold Beijing to account.

While Trump enjoyed outwardly positive relationships with both Moon and former Japanese Prime Minister Shinzo Abe, his policies toward US allies in the region were often unpredictable, veering between ramping up cooperation on some fronts, while threatening to force both Japan and South Korea to pay for US troop bases in the respective countries, or slapping them with trade tariffs.

In his speech this week, Moon appeared to criticize Trump when he welcomed the "return of diplomacy and alliance" with the US.

Such stronger ties could be of concern to Beijing, whose aggressive moves along its maritime and land borders have rattled many neighbors. India, in particular, long a neutral party in the US-China relationship, has moved much closer to Washington amid border clashes with Chinese forces in the Himalayas.

The collation has been denounced by Beijing as an anti-China bloc, but it is one that -- if translated into a more cohesive alliance -- could have a real effect in influencing Chinese policy.

And with the talks in Alaska appearing unlikely to result in closer ties between Washington and Beijing, China's leaders could be feeling apprehensive for what that could result in.