Losses to Scotch whisky exports have reached £500m as a result of tariffs imposed by the US, according to an industry body.
New figures suggest single malt exports have fallen by more than a third since a 25% tariff was imposed in 2019.
It was among measures introduced by the US in retaliation against EU subsidies given to aircraft maker Airbus.
The Scotch Whisky Association (SWA) described the current situation as "unsustainable".
It also said distillers were "continuing to pay the price for an aerospace dispute that has nothing to do" with them.
SWA chief executive Karen Betts said: "Since tariffs were put in place, our exports to the US have fallen by 35%, amounting to over half a billion pounds in lost exports.
"This is being borne by large and small producers alike, who are losing sales and market share in what has been for decades the industry's largest and most valuable market, which they may never now recover."
Ms Betts added that it is hard for Scotch whisky producers to understand why the UK government is "unwilling" to comply with World Trade Organisation rules on aerospace subsidies.
She said: "Distillers are suffering terrible losses and still the government, after 16 years of unsuccessful litigation, is unprepared to take the necessary steps to ensure subsidies comply with the UK's international obligations."
Last month, Labour leader Sir Keir Starmer used a newspaper column to call on the UK Government to negotiate with the new US administration of President Joe Biden.
As well as calling for the immediate suspension of tariffs, the SWA wants more support for the industry given the difficult trading conditions as a result of Brexit and the Covid pandemic.