Beijing: China on Saturday angrily hit out at the latest US tariff hikes on its goods, saying a "bullying" Washington would eventually "eat its own bitter fruit".
European leaders have also warned US President Donald Trump of the dangers of trade skirmishes with China and Europe, which look set to dominate the G7 summit due to begin in France.
Trump on Friday increased existing and planned tariffs on a total of $550 billion in Chinese goods, in response to new tit-for-tat levy hikes announced earlier that day by Beijing on $75 billion of US imports.
A Chinese commerce ministry spokesman on Saturday denounced Washington´s "unilateral and bullying trade protectionism".
The tariff increase "seriously undermines the multilateral trading system and the normal international trade order, and the US will surely eat its own bitter fruit.
"The Chinese side strongly urges the US side not to misjudge the situation, not to underestimate the determination of the Chinese people, and immediately stop its mistaken actions, otherwise all consequences will be borne by the US," the spokesman said.
By the end of the year the feud will affect nearly all imports and exports between the two countries, with US companies -- many of whom rely on China for inputs -- particularly worried by the rapidly changing conflict.
EU Council President Donald Tusk on Saturday warned that Trump´s escalating trade tensions with China and Europe could force economies around the world into recession.
Meanwhile, British Prime Minister Boris Johnson said he was "very concerned" about the trade tensions between the US and China, saying their tit-for-tat tariff hikes were harmful for the global economy.
"I´m very worried about the way it´s going, the growth of protectionism, of tariffs that we´re seeing," Johnson said as he arrived at the G7 summit in the French resort of Biarritz, where he was to make his full international debut as Britain´s premier.
"Those who support tariffs are at risk of incurring the blame for the downturn in the global economy," he said. "This is not the way to proceed."
The question of tariffs is of particular concern for Johnson as he prepares to lead Britain out of the EU with the prospect of a no-deal Brexit on October 31 looking increasingly likely -- which experts warn would cost both sides dearly.
His remarks echoed earlier warnings from the European Union, which warned that the escalating trade spat between Washington and Beijing could drive economies around the world into recession.
French President Emmanuel Macron, who is hosting the summit, also weighed in, saying trade tensions were "bad for everyone".
"We have to achieve some form of de-escalation, stabilise things, and avoid this trade war that is taking place all over," he said, just hours after Trump threatened to impose heavy punitive tariffs on France over its tax on US tech giants.
Trade disputes appear set to dominate the agenda of this year´s G7 summit, with Tusk and Macron warning that an ambitious deal between the EU and Latin America´s Mercosur bloc was at risk over Brazil´s response to wildfires in the Amazon. But Tusk also said the EU would respond in kind if the US imposed tariffs on French wine.