Two Americans are being detained in China in apparent retaliation for the arrest of a Chinese official in New York on visa fraud charges.

“We are aware of the detention of two U.S. citizens in Jiangsu, China, and the charges being brought against them by the provincial government,” said a State Department official. “We take seriously our responsibility to assist U.S. citizens abroad and are monitoring the situation.”

The Americans were identified by people close to the matter as Jacob Harlan and Alyssa Petersen, who were arrested last month and charged with illegally moving people across borders. They are being held at a detention facility in Jiangsu province, near Shanghai.

Mr. Harlan is the founder of China Horizons, a group that arranges for Americans to teach English in China, and Ms. Petersen is assistant director of the group.

A person familiar with the case said the timing of the arrests coincided with the arrest of a Chinese official in New York on visa fraud charges. The detentions in Jiangsu appear to be a Cold War-style hostage-taking, the source said.

The China Horizon website says Mr. Harlan has taught English in China since 2002 and notes that Ms. Petersen has spent the past eight years in and out of China. China has used detentions of foreign nationals in the past in response to arrests of Chinese officials overseas.

For example, as many as 11 Canadians were arrested in China on questionable criminal charges following the Dec. 1 arrest by Canadian authorities of Meng Wanzhou, chief financial officer of Huawei Technologies.

Ms. Meng’s arrest was carried out in response to Justice Department information that she was linked to trade with Iran in violation of U.S. sanctions.

China also arrested a Canadian couple, Kevin and Julia Garratt, in 2014 and held them for nearly two years on trumped-up spying charges.

Their arrests were carried out in apparent retaliation for the arrest by Canadian authorities of Chinese hacker Su Bin, who was later imprisoned for his role in stealing Boeing C-17 secrets as well as data on F-35 and F-22 jets.

The detentions follow the FBI’s arrest Sept. 13 of Chinese government official Zhongsan Liu after a lengthy investigation into Chinese visa fraud related to Beijing’s efforts to garner American high technology at U.S. universities.

According to court papers, Mr. Liu headed a Chinese front group in New Jersey called the China Association for International Exchange of Personnel (CAIEP).

The case also involves contacts between Mr. Liu and a Chinese government-funded Confucius Institute on a U.S. university campus.

Around 100 Confucius Institutes in the United States have come under fire from critics who say they are being used for Chinese influence operations in support of the Beijing government.

The location of the Americans’ detention also suggests linkage to another FBI case: the detention in October 2018 of Yanjun Xu, a Ministry of State Security intelligence officer indicted on charges related to the theft of aviation trade secrets.

Mr. Xu is deputy division director with the MSS’s Jiangsu State Security Department, a unit that has been linked to trade secrets’ theft.

Mr. Liu was charged with conspiracy to fraudulently obtain U.S. visas for Chinese officials involved in an effort to recruit Asian-Americans and others who have valuable high-technology experts. Six universities that were not named in court papers were targets of the scheme. They were located in Massachusetts, Georgia, New Jersey and elsewhere.

According to the FBI criminal complaint, Mr. Liu worked to obtain J-1 research visas to support Chinese scholars in the United States.

Prosecutors, however, charged that Mr. Liu secured the visas “with the knowledge that, once in the United States, the CAIEP employees would not in fact principally conduct research on behalf of their sponsoring universities, but rather would work fulltime for CAIEP.”

The operation was part of a Chinese government recruitment plan called the Thousand Talents Program, aimed at gaining American technology and intellectual property.

The Pentagon’s most recent annual report on the Chinese military stated that the Thousand Talents Program funnels technology to the Chinese military and civilian sectors. A White House report published in 2018 stated that more than 44,000 highly skilled overseas Chinese have returned to China through the programs.

At the time of Mr. Liu’s arrest, Assistant Attorney General John C. Demers, director of the National Security Section, said the United States will prosecute government-backed visa fraud while welcoming Chinese researchers.

“We will continue to confront Chinese government attempts to subvert American law to advance its own interests in diverting U.S. research and know-how to China,” he said.

In Beijing, Chinese Foreign Ministry spokesman Geng Shuang confirmed that Mr. Harlan and Ms. Petersen were detained. “The case handling organ has timely notified the U.S. Consulate-General in Shanghai and arranged consular visits of American consular officials,” he said.

Mr. Geng said he did not see a connection between the case and current U.S.-China relations.

POMPEO ON CHINA

Secretary of State Mike Pompeo has revealed that the United States will insist on strict verification measures for any future trade deal with China.

In an interview for my book “Deceiving the Sky: Inside China’s Drive for Global Supremacy,” Mr. Pompeo outlined the Trump administration’s new get-tough policy toward China. Asked about China’s past failure to abide by agreements made with the United States, Mr. Pompeo said the issue is something “we face in every negotiation.”

“The answer is always really very simple: Whatever outcomes are determined have to be verifiable,” Mr. Pompeo said.

“They have to have a methodology by which enforcement can take place, which means sharing of information and transparency so that we can see what the other side is doing so you can understand if, in fact, they’re abiding by the agreement.”

Additionally, a trade deal will need “enforcement mechanisms.”

“There needs to be things that happen in the event that one side or the other — in this case you’re referring to Chinese malfeasance — but one side or the other doesn’t abide by their agreements,” Mr. Pompeo said.

“There needs to be a built-in mechanism inside the agreement that says we’re going to verify, we’re going to have an evaluative process, and then in the event there are breaches of the agreement that one side or the other is not living up to their commitments, that there is an enforcement mechanism.”

The enforcement mechanism could include a withdrawal from the agreement or other tools that could be used that would “bring to bear to convince both parties that it is appropriate, when a commitment is made, that one needs to honor it.”

Asked if such mechanisms can be reached in a trade deal, Mr. Pompeo said, “Only time will tell.”

China already backed out of a draft agreement with the Trump administration reached in May that would have recognized China’s unfair trade practices and illicit activities.

Last week, President Trump announced a partial trade deal he described as Phase 1 had been reached and would involve the United States holding off on further tariffs in exchange for China’s purchase of billions of dollars worth of American farm products.

However, Bloomberg News reported Monday that China wants more talks before signing the partial deal and will be sending a delegation of negotiators to Washington headed by Vice Premier Liu He.

Additional talks are needed before Chinese President Xi Jinping signs the agreement, according to the news agency, quoting people familiar with the matter.

An agreement could be signed during the APEC summit in Chile next month.

The Chinese are seeking a halt in additional U.S. tariffs planned for December in addition to the tariffs that were to go into effect this week.

• Contact Bill Gertz on Twitter @BillGertz.