Walmart, Target and more than 600 other companies have urged US President Donald Trump in a letter to resolve the trade dispute with China, saying tariffs hurt American businesses and consumers. 

This letter is the latest of many sent to the Trump administration by Tariffs Hurt the Heartland.

This is the US national campaign against tariffs supported by more than 150 trade groups representing agriculture, manufacturing, retail and tech industries. 

But it is significant as US-China trade tensions escalate and comes before a possible meeting between Trump and Chinese President Xi Jinping at the June 28-29 G20 summit in Osaka, Japan. 

Trump has said he wants to meet Xi there and will decide on whether to extend tariffs to almost all Chinese imports after that. 

With less than three weeks to go before talks between Chinese and US leaders, expectations for progress toward ending the trade war are low. 

Sources have told Reuters there has been little preparation for a meeting even as the health of the world economy is at stake. 

"We remain concerned about the escalation of tit-for-tat tariffs," the new letter sent yesterday said. 

"Broadly applied tariffs are not an effective tool to change China's unfair trade practices. Tariffs are taxes paid directly by US companies, not China," it added. 

Walmart, the largest US private sector employer and the world's largest retailer, has said tariffs will increase prices for US consumers.

"Trade overall has been good for Americans, good for consumers and I realise it gets criticised at times," Walmart chief executive Doug McMillon said last week. 

He urged the Trump administration focus on how trade helps a broad number of people in the country and "not just those it harms." 

Additional 25% tariffs on $300 billion in imports, on top of those already levied, would wipe out more than 2 million US jobs, the letter said, citing estimates from international consultancy the Trade Partnership. 

They would also add more than $2,000 in costs for the average American family of four and reduce the value of US Gross Domestic Product by 1%, it said. 

"An escalated trade war is not in the country's best interest, and both sides will lose," the letter said.