On the eve of President Trump's first visit to China's capital, his favorite social media platform, Twitter, doubled its character limit for tweets to 280, offering twice the fun for America's tweeter in chief. Not so much for his hosts here.

Twitter, like Facebook, is banned in China, where President Xi Jinping has overseen a deepening crackdown on the Internet, using the "Great Firewall" to stifle self-expression in the name of bolstering the Communist Party's already tight grip over society.

Foreigners are generally still able to tweet via their cellphones, and Trump promptly resumed tweeting after a short respite while touring the Forbidden City and having dinner with Xi. In one, he thanked Xi for the hospitality, and in another, he again warned North Korea not to "underestimate" the United States.

It's what he might choose not to say that could send a more subtle but equally important message during his two-day state visit that continues Thursday with bilateral meetings and a lavish banquet.

Like his predecessors, Trump is assessing how to deal with a rising China, balancing the costs of pushing the authoritarian ­government for political and ­economic reforms with the benefits of maintaining productive ­partnerships with the world's second-largest economy.

[Xi showed his hand, now it’s time for Trump to play his cards in Asia]

Trump's predecessor, Barack Obama, spoke out in support of free speech in two visits to China. But Trump, who has belittled the press back home, has shown little inclination to confront Xi on the issue despite having once boasted he was the world's most-followed politician on social media.

"I am not holding my breath, given his track record of statements attacking the U.S. news media, labeling news reports he doesn't like as 'fake' and threatening retaliation of various kinds against news organizations," said Rebecca MacKinnon, an American who worked in China as a journalist and now runs the Ranking Digital Rights project at the New America think tank in Washington.

She added that "the biggest fear of the human rights community isn't that Trump will be silent about China's Internet controls and human rights record, but that he might say things that could be construed by the Chinese government and state-controlled media as supportive of Xi's approach."

Xi has emerged more powerful after the 19th Communist Party Congress last month, and experts said he will be emboldened to continue his consolidation of power. For Trump, who entered the three-day state visit dogged by political troubles at home, the dynamic raises the stakes in his negotiations with Xi on North Korea, trade and, potentially, human rights if the U.S. president decides to bring up the issue.

[In hard-line speech, Trump warns North Korea: ‘Do not underestimate us’]

Trump has sent mixed signals on his mind-set toward Beijing. He signed an executive order in September authorizing the Treasury Department to pursue economic sanctions on foreign companies and banks that do business with North Korea. China is by far the North's largest trading partner.

At the same time, Trump has heaped praise on Xi. During a news conference in Seoul on Tuesday, Trump praised Xi for being "very helpful" on North Korea, adding that China is "trying very hard to solve the problem."

On Wednesday, Trump mischaracterized the nature of Xi's success at the party congress, writing on Twitter that he was looking forward "to meeting with President Xi who is just off his great political victory."

China has a one-party system of authoritarian rule.

Xi welcomed Trump, who flew to Beijing after delivering a hard-line speech against North Korea at the South Korean National Assembly, with a "state visit-plus" that opened with the tour of the ancient Forbidden City, a reminder of China's 5,000 years of history. The Trumps also were treated to performances by the Peking Opera, including scenes from "The Monkey King" and "A Tipsy Beauty."

Xi has been attempting to re-elevate his country to a position of dominance in Asia and make it coequal to the United States on the world stage, with its economic growth offered as an alternative model to U.S.-style free-market capitalism.

The Trump administration has responded by framing his 12-day, five-nation Asia trip as a broadening of U.S. policy in the "Indo-Pacific" region. The administration's inclusion of India as a partner in its strategy has been read by some in Beijing and elsewhere as a bid to contain China, which Trump aides deny.

"I don't think anybody would be able to contain China," Cui Tiankai, China's ambassador to Washington, told reporters ahead of Trump's trip. "President Xi has always said that the Pacific Ocean is large enough to accommodate the development of both China and the United States."

Trump is scheduled to deliver a speech outlining his vision for the U.S. role in the region during the Asia-Pacific Economic Cooperation forum in Danang, Vietnam, this week. China's aggressive maritime expansion in the South China Sea, which the Obama administration had sought to roll back, is likely to be among the topics during Trump's meetings with Southeast Asian leaders in Vietnam and the Philippines before he returns to Washington.

At a news conference in Tokyo this week, Trump said he likes Xi "a lot" and considers him a friend. He added that he remains concerned about a trade imbalance in China's favor and vowed that "the United States will take very, very strong action" on pushing Beijing for greater market access for U.S. firms.

"The problem we have with China is that for decades . . . it's been very unfair" on trade, Trump said.

"There have never been more challenging issues to address," said Tim Stratford, managing partner of Covington & Burling's Beijing office and a former assistant U.S. trade representative. "This is as important a time for high-level dialogue as any time over the last 35 years."

U.S. companies, including technology firms such as Google, Facebook and Twitter, have complained for years about China's Internet censorship, and some have made concessions to do business in the world's most populous country. Several years ago, the Communist Party attempted to limit the renewals of some visas for U.S. journalists from the New York Times and Bloomberg News over stories that revealed a web of hidden wealth and corruption among top party officials, prompting public and private objections from the Obama administration.

Some U.S. experts said it is unlikely Xi will make concessions on issues involving free speech even if Trump does raise them.

"Consolidating state power over the Internet is a top priority for Xi — both economically and for state security," said Ian Bremmer, president of Eurasia Group, a global risk assessment firm. "A read of their [artificial intelligence] strategy shows they've put more thought into this than any other government out there, and they're just getting started."

Emily Rauhala in Beijing contributed to this report.

Read more:

Trump strikes at the heart of the North Korean regime with speech