China has lashed out at the United States for its “uncooperative” attitude and suggested it is becoming a haven for Chinese criminals, after Washington accused Beijing of deploying “covert agents” on American soil in a bid to snare fugitives wanted as part of president Xi Jinping’s war on corruption.

With just weeks to go until Xi makes his first state visit to the US, American officials have reportedly demanded Beijing stop sending undercover Chinese law enforcement agents there to take part in what Beijing calls “Operation Fox Hunt”.

The campaign to bring fugitives back to China is a key element of Xi’s high-profile offensive against corruption in the ruling Communist party.

China is understood to have handed lists of targets to countries including the US, Australia, France, Canada and the UK.

However, there is “escalating anger” in Washington over the “strong-arm tactics” – including intimidation and threats – allegedly being used by Chinese agents to bring fugitives home, the New York Times reported on Sunday.

US officials said they had solid evidence the agents were not in the US “on acknowledged government business” and were likely coming into the country on tourist or business visas.

The issue has added to tensions between the two countries ahead of Xi Jinping’s trip to the US in September.

Already this year, the countries have locked horns over issues including the alleged hacking of millions of US government personnel files and China’s artificial island building campaign in the South China Sea.

Among those whose return Beijing is demanding is Ling Wancheng, a rich and well-connected businessman who had reportedly been living in California. Ling’s brother – a former presidential chief-of-staff called Ling Jihua – was arrested and expelled from the Communist party last month and his whereabouts are currently unknown.

China’s state-controlled media reacted angrily to US claims that its agents were operating outside the law.

“The ‘Chinese secret agents’ are nothing but a fantasy,” the Global Times, a pro-Beijing tabloid, complained in an editorial on Tuesday. “The Chinese police officers set foot on the US soil by legal means and they take actions that are fair and square.

“The US government is becoming more uncooperative with China in its anti-corruption endeavors [and] the US media falsely accused China of using Operation Fox Hunt to deploy secret agents on US soil,” added the newspaper, whose stridently nationalist views sometimes reflect those of the central government.

“The US is providing shelter to those on the run. We have reason to suspect that the US wants to divert attention and regain the moral high ground.”

Xinhua, Beijing’s official news wire, said US attempts “to force China’s law enforcement staff to leave the country obviously reveals that Washington lacks sincerity”.

“The United States, as a country that often stresses the rule of law, should clarify the issue and by no means become a safe haven for Chinese criminal suspects,” it added.

In a front-page story, the China Daily cited a source in China’s Ministry of Public Security who admitted its agents had travelled abroad in an attempt to “persuade” suspects “to come back to confess their crimes”. However, the source insisted such agents were strict about doing so on “official visas”.

The Global Times’ editorial claimed that apart from the US, “no other countries have issued complaints about the operation or conspired tales of ‘secret agents’ to hinder the process”.

However, officials from other countries targeted by Operation Fox Hunt, while publicly supportive of the campaign, privately express deep unease at its modus operandi.

Some worry about the tactics being used by Xi Jinping’s corruption-busting teams and suspect some targets are the victims of political vendettas rather than genuine corruption investigations.

Others believe Beijing is exaggerating the scale of its “fox hunt” in an attempt to convince the Chinese public that it is winning the war on corruption.

“In principle, foreign governments will say: ‘Yes, of course we will support clamping down on corruption because it does impact on foreign interests in China.’ But in practice I am sure that they will have lots of questions about the methods being used and the people being pursued,” said Kerry Brown, the director of the China Studies Centre at the University of Sydney and a former British diplomat in China.

“If they are aware that there is a political agenda – and there probably is in most of these cases – then they have to be very, very careful.”

During a visit last year to the Beijing headquarters of China’s anti-corruption agency, Brown said officials had talked about the “innovative investigative methods” being used by its agents.

“Part of that is making up the rules as you go along, part of it is ends justifying means and part of it is making sure that you have always got the upper hand and you are concealing your intentions. It’s a lot of smoke and mirrors stuff.”

Brown said Beijing boasting that it was sending agents abroad was most likely intended to impress Chinese citizens but it had not played well with foreign governments.

“China certainly doesn’t like foreign agents operating on Chinese territory, so why on earth should the rest of the world embrace Chinese foreign agents operating on their territory?” he said.