WASHINGTON (Reuters) - U.S. President Donald Trump predicted on Sunday that China would take down its trade barriers, expressing optimism despite escalating trade tensions between the world’s two largest economies that have roiled global markets in the past week.

The two countries have threatened each other with tens of billions of dollars’ worth of tariffs in recent days and Chinese officials have said this is not the time for negotiations.

But Trump administration officials have stressed that the tariffs are not yet in place and the dispute could be resolved through talks.

In a Twitter post on Sunday, Trump echoed this, saying “China will take down its trade barriers because it is the right thing to do. Taxes will become reciprocal and a deal will be made on intellectual property.”

He referred to his personal relationship with Chinese President Xi Jinping and said the two men would always be friends, adding, “Great future for both countries!”

There has been no indication that Trump and Xi have had any conversations since the trade conflict erupted last week and no formal trade talks between the United States and China have been scheduled yet.

On Tuesday, Washington unveiled some $50 billion worth of proposed tariffs on Chinese imports and on Thursday Trump upped the ante, directing U.S. trade officials to identify tariffs on another $100 billion of Chinese imports. He said this was “in light of China’s unfair retaliation” against the earlier U.S. trade action.

China responded by saying it was fully prepared to respond with a “fierce counter strike” if the United States followed through on the new threat.

China’s Commerce Ministry spokesman, Gao Feng, said on Friday that Trump’s threat of another package of tariffs was “extremely mistaken” and unjustified, adding no negotiations were likely in the current circumstances.

Crude oil and global equity markets tumbled on Friday on investor worries about the impact a tariff war could have on the world economy.

‘FIRMLY ATTACKED’

China’s state media has sharply criticized the United States, saying its trade protectionism actions will end in defeat. “If the U.S. says that it will pay any price, it must be firmly attacked,” China’s official Xinhua news agency said on Saturday.

On Sunday, the state People’s Daily newspaper sought to tap into concern among some U.S. business leaders over the impact of Washington’s planned tariffs.

FILE PHOTO - Containers are seen at the Yangshan Deep Water Port, part of the Shanghai Free Trade Zone, in Shanghai, China March 14, 2018. REUTERS/Aly Song

“We call on the international business community including the United States industrial and commercial circles to take prompt and effective measures and urge the U.S. government to correct its errors,” it said.

Trump’s chief economic adviser, National Economic Council Director Larry Kudlow, has repeatedly sought in recent days to soothe concerns about a trade war, stressing that no tariffs have yet been implemented.

He reiterated that in an interview on CNN’s State of the Union show on Sunday, saying, “This process might turn out to be very benign ... Maybe China will want to come round and talk in earnest - so far it hasn’t, I hope it does.”

The United States, charging China with unfair trade practices and theft of intellectual property, proposed some $50 billion in tariffs on Tuesday - 25 percent tariffs on more than 1,300 Chinese industrial and other products from flat-panel televisions to electronic components.

China shot back within hours with its own list of proposed duties on $50 billion of American imports, including soybeans, aircraft, cars, beef and chemicals.

U.S. Treasury Secretary Steven Mnuchin said on the CBS program Face The Nation there was a risk of a trade war between the United States and China but that he did not expect one.

He added that Trump and Xi have a “very close relationship” and that the United States and China would continue to discuss trade issues.