BEIJING — China warned President-elect Donald J. Trump on Monday that he was risking a confrontation over Taiwan, even as Mr. Trump broadened the dispute with new messages on Twitter challenging Beijing’s trade policies and military activities in the South China Sea.
A front-page editorial in the overseas edition of People’s Daily, the official organ of the Communist Party of China, denounced Mr. Trump for speaking Friday with Taiwan’s president, Tsai Ing-wen, warning that “creating troubles for the China-U.S. relationship is creating troubles for the U.S. itself.” The rebuke was much tougher than the Chinese Foreign Ministry’s initial response to the phone call, which broke with decades of American diplomatic practice.
For his part, Mr. Trump seemed to take umbrage at the idea that he needed China’s approval to speak with Ms. Tsai. In two posts on Twitter, he wrote: “Did China ask us if it was O.K. to devalue their currency (making it hard for our companies to compete), heavily tax our products going into their country (the U.S. doesn’t tax them) or to build a massive military complex in the middle of the South China Sea? I don’t think so!”
China often uses the overseas edition of People’s Daily to test-run major policy pronouncements. In a pointed rejoinder to Mr. Trump, the editorial said that pushing China on Taiwan “would greatly reduce the chance to achieve the goal of making America great again.”
By going after China’s policies on trade and security, Mr. Trump appeared to be confirming his intent to take a tougher line with the Chinese leadership across a broader range of issues — and further dampened hopes in Beijing that he might step back from the campaign rhetoric he has used, including threats of punishing trade tariffs.
That could put President Xi Jinping in a difficult position, forced to choose between playing down Mr. Trump’s attacks and risking a backlash at home, or raising the stakes by pushing back more forcefully and setting China on a potential collision course with the United States, its most important trading partner.
The Chinese government’s initial reaction to Mr. Trump’s call has already faced a torrent of criticism on social media from Chinese who complained it was not tough enough. The statement from Foreign Minister Wang Yi, which was relatively low-key given the unprecedented nature of the call, refrained from criticizing Mr. Trump, instead accusing Taiwan of playing a “little trick” on the American president-elect.
That offered Mr. Trump a face-saving way out of the imbroglio, and a chance to de-escalate. But the messages he posted on Twitter late Sunday stepped up the pressure on China’s leaders instead.
Some Chinese analysts see Mr. Trump as striking out early on a starkly different path from President Obama’s, determined to strenuously compete with China on economic issues.
In the last four years, Mr. Obama has stressed cooperation with Beijing, particularly on the Paris international climate accord, which the Chinese government saw as being in its own interest because of its public’s anger over pollution. Mr. Obama veered away from bargaining on issues like China’s protected marketplace and its repressive human rights situation, even though some officials in his administration have privately argued he could have obtained concessions in those areas.
By contrast, Mr. Trump is looking like a negotiator from the start, some Chinese analysts said. “By showing strength at the beginning, he may hope to gain advantages in bargaining later with the Chinese on many key issues,” Zhang Baohui, a professor of international relations at Lingnan University in Hong Kong, said of Mr. Trump. “He is a businessman, and he could be bringing his business bargaining tactics to interstate relations.” Thus, he said, there was “strategic logic” to Mr. Trump’s actions in the past few days.
Another Chinese state newspaper, the hawkish Global Times, called Mr. Trump a “neophyte” in diplomatic affairs, and some Chinese reports have suggested that the president-elect did not understand the import of his phone call with Ms. Tsai. But Mr. Trump’s follow-up messages on Twitter seemed to show he had been well briefed on Taiwan and questions of trade and the South China Sea.
The call with Ms. Tsai and the Twitter posts reflected the views of Trump advisers with Asia experience, such as John Bolton, whom Mr. Trump is said to be considering as his secretary of state. Mr. Bolton served during the administration of George W. Bush in the early 2000s as under secretary of state for arms control and international security affairs, and in the mid-1990s he wrote research papers for the Taiwan government.
Mr. Bolton said Saturday of China that it was to time to “shake the relationship up,” noting what he called its “aggressive and belligerent claims” in the South China Sea. “Nobody in Beijing gets to dictate who we talk to,” Mr. Bolton said on Fox News.
Reince Priebus, Mr. Trump’s choice for chief of staff, who has been described in Taiwan’s news media as a good friend of Taiwan, said in his own Fox News appearance Saturday that Mr. Trump “knew exactly what was happening” when he spoke with Ms. Tsai on Friday.
Jon Huntsman, a former ambassador to China who is also said to be under consideration for secretary of state, called Mr. Trump’s call “shrewd” on Saturday, saying it would provide a “useful leverage point” with Beijing. Mr. Huntsman spent two stints in Taiwan, first as a Mormon missionary and later as an executive for a company his family owned.
In Mr. Trump’s Twitter messages late Sunday about China, two of his three assertions were essentially correct, including his reference to the South China Sea. In the last several years, China has built artificial islands in the Spratly archipelago in the South China Sea, and it has constructed military airstrips and naval berths on three of them.
During the construction phase, the Obama administration insisted that the South China Sea was an international waterway, and it used freedom of navigation patrols by the United States Navy to make that point. Some American critics who believed Mr. Obama should have shown a stronger hand approved of Mr. Trump’s statement.
“Mr. Trump’s tweets and actions appear to be more than a symbolic act,” said James E. Fanell, a former director of intelligence and information operations for the United States Pacific Fleet. “This will upset Beijing, but it is going to remind the rest of the Indo-Asia Pacific region that the new administration is not going to be fettered by the past.”
On trade, Mr. Trump was also broadly accurate. When China joined the World Trade Organization in late 2001, it was treated as a developing country, allowed to retain higher tariffs than industrialized countries to protect its industries.
China reduced its high tariffs on imported cars, but only to 25 percent. By contrast, the United States imposes a 2.5 percent tax on imported cars. Many other goods entering China also face tariffs of 20 percent to 25 percent, while the United States has eliminated tariffs on a broad range of imports and kept tariffs at 2.5 percent or less for most other categories.
But Mr. Trump’s assertion that China had devalued its currency — one he made frequently during his campaign — is out of date. In recent years, China has allowed its currency, the renminbi, to strengthen, to make it more appealing to global investors.
Last year, the International Monetary Fund said the renminbi was no longer undervalued, after a decade of saying that it was. But a few months later, China devalued the renminbi, in a move that shocked the markets, and has since let it become weaker still.
The difference is that these days, Beijing — worried about people and companies taking money out of the country — is trying to slow that fall. Many economists and investors believe the renminbi should weaken because China’s growth is slowing. But China has been dipping into its currency reserves and making other moves to moderate the drop. Without those efforts, many economists believe, the currency would be even weaker than it is now.