WASHINGTON/BEIJING (REUTERS) - US President Donald Trump set the tone for a tense first meeting with Chinese President Xi Jinping next week by tweeting on Thursday (March 30) that the United States could no longer tolerate massive trade deficits and job losses.

The White House said Trump would host Xi next Thursday and Friday at his Mar-a-Lago retreat in Florida. It said Trump and his wife Melania would host Xi and his wife Peng Liyuan at a dinner next Thursday.

In a tweet on Thursday evening, Trump said the highly anticipated meeting between the leaders of the world's two largest economies, which is also expected to cover differences over North Korea and China's strategic ambitions in the South China Sea, "will be a very difficult one."

"We can no longer have massive trade deficits and job losses," he wrote. "American companies must be prepared to look at other alternatives," he said in apparent reference to US firms manufacturing in China.

Despite a string of US-China meetings and conversations that have appeared aimed at mending ties after strong criticism of China by Trump during his election campaign, US officials have said the Republican president will not pull his punches at the meeting.

General Electric Co Chief Executive Officer Jeff Immelt urged Trump on Thursday to maintain the country's economic relationship with China, saying the United States had much to gain from globalisation.

"The country loses if we don't trade. The relationship with China is key," Immelt told an aviation panel hosted by industry group the Wings Club. "If you give up on trade, you give up on the best lever that the president of the United States has in negotiating around the world. I just think that President Trump is too smart to give up on that."

The US Commerce Department said earlier that Beijing must change its trade practices and the way its state enterprises operate.

"China and others need to realise the game is over - continuing their unfair trade practices and operation as a non-market economy will have serious consequences," it said.

The department said it was launching a new review of China's status as a non-market economy, which allows the United States to maintain high anti-dumping duties on cheap Chinese imports, but the designation is widely expected to remain in place.

Chinese Foreign Ministry spokesman Lu Kang stressed the need to see the big picture while fostering mutual trade interests.

"The market dictates that interests between our two countries are structured so that you will always have me and I will always have you," he told a regular briefing. "Both sides should work together to make the cake of mutual interest bigger and not simply seek fairer distribution."

'BIG ISSUES'

Trump administration officials say the need for China to do more to rein in the nuclear and missile programs of its neighbour and ally North Korea will top the agenda, along with trade. The US side is also expected to criticise Beijing for its pursuit of expansive claims in the South China Sea.

White House spokesman Sean Spicer told a news briefing the meeting would be an opportunity for Trump "to develop a relationship in person with President Xi."

"He's spoken to him on the phone a few times, but we have big problems ... everything from the South China Sea, to trade, to North Korea. There are big issues of national and economic security that need to get addressed."

Asked if the administration had a vision, or a description for its China policy like the "pivot" or "rebalance" to Asia touted by former President Barack Obama, Spicer said: "Right now we're not worried so much about slogans as much as progress.

"There's a lot of big things that we need to accomplish with China, and I think that we will - we will work on them."

US Secretary of State Rex Tillerson agreed in Beijing this month to work with China on North Korea and stressed Trump's desire to enhance understanding.

China has been irritated at being told repeatedly by Washington to rein in North Korea's nuclear and missile programs, or face US sanctions on Chinese businesses trading with North Korea, and by the US decision to base an advanced missile defence system in South Korea.

Beijing is also deeply suspicious of US intentions toward self-ruled Taiwan, which China claims as its own, after Trump, as president-elect, broke with decades of US policy by taking a phone call from Taiwanese President Tsai Ing-wen and saying Washington did not have to stick to a "one China" policy.

Trump later agreed in a phone call with Xi to honour the long-standing policy and has also written to him since seeking "constructive ties."