A senior Chinese official has said the “external forces” that instigated the political turmoil in Hong Kong are also trying to infiltrate Macau.

The claim was made in an essay by Zhang Xiaoming, Beijing’s top official in charge of Hong Kong and Macau affairs, that was published in the latest issue of Qiushi (Seeking Truth), a bimonthly journal produced by the Chinese Communist Party.

The article came after Chinese President Xi Jinping visited Macau last month to mark the 20th anniversary of the enclave’s return to Chinese rule.

Zhang quoted Xi, who is also general secretary of the Communist Party, as saying that China was firm in safeguarding “national sovereignty, security and people’s interests” and would never tolerate foreign interference in Hong Kong or Macau.

“These comments by general secretary Xi Jinping were a head-on blow to them and meant to serve as an encouragement to us in our rightful struggle and counteractions when external forces are deeply involved in the extradition bill’s turmoil, taking part in and manufacturing the chaos in Hong Kong, and they are also trying to infiltrate Macau,” he said.

Zhang said Hong Kong had suffered “setbacks” but Macau had made great strides in implementing the “one country, two systems” governance model. He said the two cities were different but what Xi said in Macau should serve as “important guidance” for Hong Kong.

For months, Beijing has blamed foreign powers for instigating the unrest in Hong Kong, which began in June with a mass rally to oppose a now scrapped extradition bill. It has simultaneously praised Macau for maintaining social stability and economic prosperity, but never suggested that foreign forces were targeting Macau.

A foreign ministry spokesperson said earlier that the unrest in Hong Kong was “the work of the US”, citing comments from politicians in Washington who have expressed sympathy for the pro-democracy movement in the city.

After the US Congress passed a bill that increased Washington’s scrutiny of Hong Kong, Beijing retaliated by suspending visits of US military vessels to the city and sanctioning several US-based non-government organisations.

Lau Siu-kai, vice-chairman of the Chinese Association of Hong Kong and Macau Studies, a semi-official think tank, said Beijing’s concerns about Macau were likely related to those organisations.

“Beijing has long had national security concerns about Macau and much of that concern has involved the US,” he said.

“But foreign organisations have had problems establishing a presence in Macau so Beijing believes they are more likely [to build their] influence through [their presence] in Hong Kong.”

Lau said that although Beijing wanted Macau to diversify its economy and open up to foreign investment, it would also keep its guard up against foreign influence.

“Beijing might think that it has less to fear for Macau as it is not as developed [as Hong Kong], but its concerns will rise when it seeks to push Macau to become more international,” he said.