It's minus 20 degrees Celsius in this refrigeration hall in Shanghai. But outside, a trade war is heating up.

US Pork and beef have been targeted by China in the first round of the trade war.

Beijing is aiming at US President Donald Trump's core supporters, the US farmers.

HAN PENG SHANGHAI "Most of the US pork exports to China are not really the major part of the pig. They are something like this: a pig face or pig feet. These are things that foreigners do not consume in their day to day lives. But they are popular ingredients that the Chinese can make into really delicious cuisines. If the Chinese stop buying them, few other countries would become huge markets for them."

Xu Wei is the general manager of one of Shanghai's largest food importers. Last year, his company was among the first in China to move after China lifted the ban on the US beef. But now his US food imports have dropped sharply.

XU WEI, GENERAL MANAGER SHANGHAI NEW SOURCE INTERNATIONAL TRADING COMPANY "We used to pay just 24% tariffs for US pork in China. But now the taxes have risen to over 50%."

Xu's wife Zhu Xiaojun runs a stylish steakhouse, one of his most loyal buyers of US meat. It's located in downtown Shanghai. The origin of the meat is clearly marked on the menu. Zhu says she is preparing to raise prices, only on US meat.

ZHU XIAOJUN, MANAGER PC WOK STEAKHOUSE "Most of our suppliers have stopped importing the beef from the US. For those that are still being sold in market, the prices have become ridiculously high."

Both of the couple say their business won't take a major blow, as they can easily find alternative suppliers from Europe and Australia.

XU WEI, GENERAL MANAGER SHANGHAI NEW SOURCE INTERNATIONAL TRADING COMPANY "It's the US producers that will suffer. Chinese people don't need imported pork or beef in their day to day life. It's a luxury that people eat as special treats."

The president of the American Chamber of Commerce in Shanghai, which represent over 16-hundred US firms is worried.

KENNETH JARRETT, PRESIDENT AMERICAN CHAMBER OF COMMERCE IN SHANGHAI "There is no winner, as you face tit-for-tat tariffs. So everybody loses. Right now, the two governments are busy calculating who is going to hurt more in the tariff war. But frankly, it's really difficult to assess, because of the nature of the global trade."

The trade war has gone far beyond just the dinner table. Last week, Trump threatened a new round of tariffs on 200 billion dollars worth of Chinese goods. Beijing warned it will fight back if Washington pulls the trigger. Han Peng, CGTN, Shanghai.