The Trump administration rejected China's appeal during the summit in Beijing to develop closer law enforcement ties amid concerns over Beijing's illegal operations in America against fugitives.
President Trump also pressed supreme Chinese leader Xi Jinping to curb exports of the drug fentanyl that has been fueling the deadly opioid crisis in the United States, according to a senior White House official in Beijing who took part in the summit.
The president also told Xi, who last month further consolidated power in a turnover of members of the seven-member Politburo standing committee, that the United States will not end arms sales to Taiwan and will continue providing defensive weaponry to the island, the official said during a telephone briefing at the end of the summit.
Chinese opposition to American arms sales to Taiwan was raised "obliquely" by the Chinese during talks Wednesday, the official said.
Trump on Thursday hailed the day-and-a-half summit a success on U.S. issues of curbing North Korea's nuclear missile programs and on balancing trade ties. The president tweeted that he hopes to build a stronger relationship with China in the coming months and years.
The president was scheduled to depart Beijing for Vietnam Friday morning. In a speech, Trump will lay out America's vision for a free and open Indo-Pacific region.
China sought to flatter Trump during the visit in hopes of winning concessions from the president on issues such as accepting China's territorial claims to disputed waters and toward recognizing China as a major world power.
Tensions with North Korea continue to be high as three U.S. aircraft-carrier strike groups are conducting exercises this week in the Sea of Japan.
"Today, President Xi and I discussed ways we can enhance coordination to better counter the deadly drug trade and to stop the lethal flow of poisonous drugs into our countries and into our communities," said Trump at a joint press briefing with Xi.
The senior official said Trump raised Chinese fentanyl exports in every meeting, noting the drug contributed to 20,000 drug overdose deaths last year.
"Chinese fentanyl that has been smuggled into our country," the official said, noting some progress in China's commitment to work much more aggressively to rein in the drug exports. A significant amount of Chinese fentanyl is coming into the United States from Mexico as well as directly through the mail from China.
The president made no mention of law enforcement cooperation or China's sub rosa intelligence operations against fugitives codenamed "fox hunt" by FBI counterspies.
Xi, however, announced in his formal remarks after the meeting that the two nations had agreed "neither wants to become a safe haven for each other's fugitives, and will instruct competent authorities of the two countries to actively explore a long-term cooperation mechanism regarding fugitive assets recovery and repatriation of illegal immigrants."
"We did not agree to such a mechanism," the senior American official said. "And we were fairly forthright in reminding the Chinese that we are a country that enjoys the rule of law, not rule by law."
The official said the U.S. side made clear to the Chinese that "we are not going to tolerate activities on our shores that violate our laws."
"And we've seen some overreach by China," the official added, referring to Chinese intelligence and security activities in the United States.
China in recent years has been conducting aggressive security operations inside the United States in a search for both criminals and political dissidents. For example, a senior Chinese security official and several others were detained briefly by the FBI in New York in May for violating travel restrictions and for extortion after meeting with dissident Chinese businessman Guo Wengui.
The State Department, however, intervened to block the FBI from arresting the Chinese. However, the officials' phones and computers were seized.
"It is a criminal offense for an individual, other than a diplomatic or consular officer or attaché, to act in the United States as an agent of a foreign power without prior notification to the Attorney General," a Justice Department official told the Wall Street Journal regarding the Chinese operation in New York that averted a major international row.
Attorney General Jeff Sessions also criticized China during a meeting in October with a senior Chinese security official after Beijing was linked to the hacking of the computer networks of the Hudson Institute think tank. The institute came under cyber attack for hosting a conference with Guo, which was later canceled by Hudson under pressure from China.
The official did not comment directly when asked if the Chinese pressed the U.S. side to return Guo Wengui, who since January has become an outspoken critic of high-level corruption among the Chinese leaders, including disclosure of secrets that have come from inside the political police and intelligence apparatus.
China has engaged in a major covert influence campaign against Guo that has included pressuring American social media companies to silence Guo outlets and using American business leaders with interests in China to lobby Trump to repatriate Guo.
In one Chinese operation, hackers believed to be linked to Beijing penetrated the computer system of Guo's lawyer and stole his application for political asylum and posted it on Twitter.
Guo said in a statement that China has been seeking long-term law enforcement cooperation for years, and Beijing interprets the cooperation as "jointly enforcing laws."
"China knows the U.S will never agree to it but keeps pushing it," he said. "The purpose is to put on a show domestically for the ruler's political enemies, and to scare the Chinese people. It is a psychological warfare."
Guo said China has sought to create "fake harmonious relations" with the United States through this effort. "It is a distraction, just like North Korea is a distraction," he said.
Guo said sources in China told him that he was not specifically mentioned by Xi in his meeting with Trump, an indication of the declining influence of Politburo member and anticorruption czar Wang Qishan, who retired from all official posts last month amid corruption allegations regarding his finances that was presented by Guo.
On Taiwan arms sales, the senior official said there were no discussions of issuing a fourth U.S.-China communique on Taiwan, or talk of a "grand bargain" with China to resolve the Taiwan issue.
The island nation is a de facto separate country, but China regards Taiwan as a breakaway province and has vowed to reunite it with the mainland.
"The president spoke of our one China policy based on the three communiqués and the Taiwan Relations Act, so we're going to continue providing defensive weapons commensurate with our obligations under the law," the official said.
The talks also included discussion of Chinese investment in the United States that is relatively unfettered compared with unfair Chinese restrictions on American investment in China.
The senior official said the Chinese raised the issue of expected tighter controls on Chinese investment through the Treasury Department-led Committee on Foreign Investment in the United States, or CFIUS.
Under Trump, CFIUS has taken a tougher stance in restricting Chinese attempts to purchase sensitive technology through acquisition of American companies.
"We're of course looking at reforming CFIUS and looking at other tools in our toolkit, and made clear to the Chinese side that some of those tool boxes have been in the basement for awhile but are still sharp and shiny," the official said. "And we're going to use the authorities that we have under our laws to mitigate the effects of China's grossly unfair economic relationship with us."
Legislation was introduced in Congress this week that would modernize the government's national security review.
Chinese investment in the United States increased more than 900 percent between 2010 and 2016, according to a key sponsor of the legislation, Rep. Robert Pittenger (R., N.C.). "Much of this investment was part of a strategic, coordinated, Chinese government effort to target critical American infrastructure," he said.
On North Korea, China agreed to "maintain pressure" on North Korea, the official said.
Some progress was made in pressing Beijing to do more in curbing North Korean nuclear and missile programs but the administration will be closely watching to see if the commitment is carried out.
Trump also raised U.S. concerns about Chinese encroachment in the South China Sea during his meetings, specifically the need to allow freedom of navigation and for China to follow international law.