WASHINGTON (BLOOMBERG) - As China awaits United States sanctions for cracking down on Hong Kong, recent murmurs in agriculture markets have increased worries that a trade deal between the world's two biggest economies could unravel.

Chinese imports of US farm goods are a cornerstone of the phase one trade deal inked in January after a lengthy tit-for-tat trade war.

Over nearly two years of talks, Beijing was careful to separate trade from political disputes with the US over issues including the pro-democracy protests in Hong Kong and restrictions on Huawei Technologies Co.

This week gave rise to questions of a shift: People familiar with the situation said that Chinese officials told state-run agricultural companies to pause purchases of some American farm goods, including soybeans, as Beijing evaluates a potential US response over Hong Kong.

There are some exceptions, one person said, and some transactions have still filtered through.

News reports of the order were likely a "trial balloon", as any halt would be a significant change in approach, said Mr Jude Blanchette, Freeman Chair in China Studies at the Centre for Strategic and International Studies in Washington.

He added that he was "very sceptical" Beijing would meaningfully stop the purchases.

"It's Beijing showing that they can act, not an action in itself," he added. "The separation of political and economic statecraft could end if the US pushed China to the point where restraint stopped looking like reasonable behaviour, and starting looking like weakness."

RETALIATION THREATS

China had agreed to buy US farm goods worth about US$36.5 billion (S$50 billion) for 2020 as part of the deal, one of the few tangible outcomes President Donald Trump has been able to tout after imposing punitive tariffs that drew retaliation, roiled both economies and upended global trade.

However, the coronavirus outbreak and already weakening demand meant China managed to import only US$3.35 billion in American agricultural products in the first three months of the year, the lowest for that period since 2007.

On top of that, bilateral relations have also deteriorated dramatically since the January signing.

Fights are brewing across a range of issues, from responsibility for the virus and 5G networks to human rights in Xinjiang and territorial disputes in the South China Sea.

China has repeatedly threatened to retaliate against the US for putting restrictions on its companies and citizens, though it has not specified what measures it will take.

Beijing has up till now refrained from using economic coercion to hit back against the US, a strategy it has employed against other smaller countries who have raised its ire.

Last month, it banned shipments of meat from some Australian exporters and slapped tariffs of more than 80 per cent on Australian barley after the country called for an inquiry into the origins of the coronavirus.

China also restricted canola imports from Canada following its 2018 detention of a Huawei executive, who is currently fighting extradition to the US.

In both cases, China cited legal and health violations and didn't connect the restrictions to the disputes.

"China has the right to adopt trade measures to let its trade partners cool their heads," said Mr Mei Xinyu, a researcher at a think tank under China's Commerce Ministry, repeating the government's stance that the Trump administration's moves against Hong Kong endanger China's national sovereignty.

"You cannot talk business with someone who stabs your back."

The Global Times, a Communist Party tabloid, ran a story on Monday citing Chinese experts who said a pause in agricultural imports could be preparation to retaliate against US measures, and such a move would be "unsurprising".

POLITICAL CLIMATE

Still, officially China says it is committed to the deal. Premier Li Keqiang last month reiterated a pledge to implement the phase one agreement during high-profile annual legislative meetings in Beijing.

But some Chinese analysts argued that was contingent on both sides maintaining political stability.

"The implementation of the phase one deal requires a peaceful and stable atmosphere, yet the US has been hurling new insults non-stop at China every a few days," said Mr He Weiwen, who previously served as a commercial attache at the Chinese consulates in New York and San Francisco.

"China does not want to politicise the trade deal, but politics will definitely deal blows to the trade deal."

Targeting agricultural imports would hurt American farmers, a key voter bloc for Mr Trump as he heads towards an election in November.

They have already received billions of dollars in aid that would cushion the impact of any restrictions.

And China currently faces a shortfall of at least 20 million tonnes of soybeans for the fourth quarter and first two months of 2021, the peak season for US sales, because of lower supply from Brazil compared with last year.

It may not be feasible for China to impose an extended halt of US soybean imports, given other major suppliers have restricted grain exports because of the pandemic.

Still, Mr Trump faces fierce domestic criticism over his response to protests raging across multiple cities over racial discrimination and police brutality, and is still struggling to contain the coronavirus that has killed more than 100,000 people.

In the current climate, US officials could be pushed to take greater risks leading to further escalation, according to CSIS' Mr Blanchette.

"The US faces simultaneous domestic and international crises," he said. "We are in for a very worrying couple of months."