* Trade and North Korea to top agenda for Trump and Xi
* Criticism of trade imbalance fuels worries of tension
* 'We need to focus on levelling playing field'
* Trump uses some of toughest language yet on N.Korea
* Xi gives Trump rare personal tour of Forbidden City (Adds comment from U.S. official, Trump's use of Twitter in China, paragraphs 11-13, 19)
BEIJING, Nov 9 (Reuters) - North Korea and trade will likely top the agenda when U.S. President Donald Trump and Chinese President Xi Jinping sit down for formal talks on Thursday, a day after Trump warned Pyongyang of the grave danger of developing nuclear weapons.
In a show of the importance China puts on Trump's first official visit, Thursday morning's welcoming ceremony outside Beijing's Great Hall of the People overlooking Tiananmen Square was broadcast live on state television - unprecedented treatment for a visiting leader.
Trump and Xi hit it off at their first meeting in April at Trump's Mar-a-Lago resort in Florida and continued their "bromance" on Wednesday with an afternoon of sightseeing together with their wives. However, deep divisions persist over trade and North Korea.
And while Xi is riding high after consolidating power at a twice-a-decade Communist Party Congress last month, Trump comes to China saddled with low public approval ratings and dogged by investigations into Russian links to his election campaign.
Trump has ratcheted up his criticism of China's massive trade surplus with the United States - calling it "embarrassing" and "horrible" last week - and has accused Beijing of unfair trade practices, fuelling worries of increased tension between the world's two largest trading countries.
For its part, China says U.S. restrictions on Chinese investments in the United States and on high-tech exports need to be addressed.
Roughly $250 billion in deals with U.S. companies are expected to be announced during the visit, people familiar with the matter said, with several corporate CEOs in Beijing as part of a delegation led by U.S. Commerce Secretary Wilbur Ross.
Some in the U.S. business community have expressed worry that contract wins could come at the expense of resolving long-standing complaints over market access restrictions in China.
"This shows that we have a strong, vibrant bilateral economic relationship, and yet we still need to focus on levelling the playing field because U.S. companies continue to be disadvantaged doing business in China," said William Zarit, chairman of the American Chamber of Commerce in China.
Trump railed against China's trade practices during the 2016 U.S. presidential campaign and threatened to take action once in office. But he has since held back on any major trade penalties, making clear he was doing so to give Beijing time to make progress reining in North Korea.
A U.S. official said both sides are "in sync" about wanting to minimise friction during the visit and recreate the positive tone of the Mar-a-Lago summit.
Trump is principally pressing China to tighten the screws further on North Korea and at least modest progress is hoped for, although there are no immediate signs of a major breakthrough, the official said.
Trump was not expected to put much emphasis in his talks with Xi on thorny issues like the disputed South China Sea and self-ruled Taiwan, claimed by China as its own, although the two presidents' aides may deal with those matters privately, the official told Reuters, speaking on condition of anonymity.
China has repeatedly pushed back at suggestions it should be doing more to rein in North Korea, which does about 90 percent of its trade with China, saying it is fully enforcing U.N. sanctions and that everyone has a responsibility to lower tensions and get talks back on track.
Trump used some of his toughest language yet against North Korea in a wide-ranging address in Seoul on Wednesday that lodged specific accusations of chilling human rights abuses, although he offered no evidence to support the accusations.
He also called on countries around the world to isolate Pyongyang by denying it "any form of support, supply or acceptance".
There was no immediate public mention of North Korea from either Trump or Xi as they wrapped up their festivities on Wednesday at the Forbidden City, where Xi gave Trump the rare honour of a personal tour of the UNESCO World Heritage site.
"Looking forward to a full day of meetings with President Xi and our delegations tomorrow. THANK YOU for the beautiful welcome China! zFLOTUS Melania and I will never forget it!" Trump said on Twitter after the visit and dinner there.
Twitter is blocked in China, and his use of the service prompted many people to comment on Chinese social media how he managed to evade China's tough internet controls. Many people use VPNs to skirt the restrictions.
Chinese state media praised the tone of the initial get-together on Thursday, part of what China has promised will be a "state visit plus" for Trump.
"Trump seems to be pragmatic on his Beijing policy, and has no interest in ideological diplomacy. He hasn't used the issue of human rights to make trouble for China so far, and this means the Sino-US relationship can focus on substantive matters," influential tabloid the Global Times said in an editorial. (Additional reporting by matt Spetalnick, Matthew Miller and John Ruwitch; Writing by Ben Blanchard and Tony Munroe; Editing by Paul Tait)