Unless you are talking a high turnover business regarding the exports to the US, I think you will find the costs involved prohibitive. Especially as the product involved is petfood. As outlined in the above post, you will certainly need to engage a broker. They may well seek a US Insurer with local Thai representation who may have a slightly more sympathetic view of the exposure. However, you are probably talking a minimum starting point of US$5-10,000 premium regardless of turnover, much higher if you have substantial turnover.
Have you been asked for a minimum limit of liability - US$ 1m, 5m, 10m?