China's President Xi Jinping waves to delegates as he is elected to a second five-year term during the fifth plenary session of the first session of the 13th National People's Congress (NPC) at the Great Hall of the People in Beijing on March 17, 2018.

Washington also said it will press ahead with restrictions on investment by Chinese companies in the United States as well as export controls for goods exported to China.

In an unexpected change in tone, the United States said on Tuesday that it still held the threat of imposing tariffs on $50 billion of imports from China unless Beijing addressed the issue of theft of American intellectual property.

China lashed out on Wednesday at renewed threats from the White House on trade, warning that it was ready to fight back if Washington was looking for a trade war, days ahead of a planned visit by U.S. Commerce Secretary Wilbur Ross .

Its tougher stance comes as President Donald Trump prepares for a June 12 summit with North Korean leader Kim Jong Un, whose key diplomatic backer is China, and as Washington steps up efforts to counter what it sees as Beijing's efforts to limit freedom of navigation in the South China Sea.

The trade escalation came after the two sides had agreed during talks in Washington earlier this month to find steps to narrow China's $375 billion trade surplus. Ross is expected to try and get China to agree to firm numbers to buy more U.S. goods during a June 2-4 visit to the Chinese capital.

"We urge the United States to keep its promise, and meet China halfway in the spirit of the joint statement," Chinese Foreign Ministry spokeswoman Hua Chunying told a daily news briefing, adding that China would take "resolute and forceful" measures to protect its interests if Washington insists upon acting in an "arbitrary and reckless manner."

"When it comes to international relations, every time a country does an about face and contradicts itself, it's another blow to, and a squandering of, its reputation," Hua said.

China has said it will respond in kind to threats by Trump to impose tariffs on up to $150 billion of Chinese goods.

Trade war fears had also receded after the Trump administration said it had reached a deal to put ZTE Corp. back in business after banning China's second-biggest telecoms equipment maker from buying U.S. technology parts for seven years.

The easing in tensions had fuelled optimism that agreement was imminent for Chinese antitrust clearance for San Diego-based Qualcomm's $44 billion purchase of Netherlands-based NXP Semiconductors, which has been hanging in the balance amid the trade dispute.

A team of Qualcomm lawyers that is expecting to meet with Chinese regulators ahead of Ross's arrival remained in San Diego as of late Tuesday, a source familiar with the matter said.

"On hold now," another person familiar with Qualcomm's talks with the Chinese government said on Wednesday, declining to be identified as the negotiations are confidential.

"Trump is crazy. Crazy tactics might work, though," the person added.