HONG KONG — Beijing has warned the ruling party in Taiwan not to “mess up” Hong Kong affairs, as Taipei prepares to help Hongkongers seeking to flee their city, where a contentious national security law has been imposed.

Ms Zhu Fenglian, a spokeswoman for Beijing’s Taiwan Affairs Office, described the independence-leaning Democratic Progressive Party as a “black hand” that wanted to undermine the prosperity and stability of Hong Kong.

“What the DPP authorities said was an undisguised distortion of facts, which served only to reveal its vicious intention to mess up Hong Kong and seek independence for Taiwan,” she said.

Ms Zhu was responding to Taiwanese President Tsai Ing-wen and her party’s comments that the new legislation violated democracy and human rights in Hong Kong, and that Taipei would offer humanitarian assistance for fleeing Hongkongers.

The national security law was passed unanimously by Beijing’s top legislative body on Tuesday and came into force that night. It punishes crimes of secession, subversion, terrorism and collusion with foreign forces with a maximum term of life imprisonment, raising fears that it will curtail freedoms and undermine the rule of law in Hong Kong.

Ms Zhu said: “Any person or force that attempts to undermine China’s national sovereignty, security, development interests, and the prosperity and stability of [Hong Kong] will … suffer the consequences.”

She said penalties under the new law would “surely cut off the ‘black hands’ of the DPP trying to mess up Hong Kong”.

Mr Chen Ming-tong, head of Taiwan’s policymaking Mainland Affairs Council hit back at Beijing on Wednesday, as he opened an office to help people who want to leave Hong Kong. He said Beijing had imposed a law on the city that penalises anyone in the world who is critical of mainland authorities.

“[This law] not only targets residents in Hong Kong. It’s actually a supreme decree issued by the Celestial Empire to people all over the world,” he said, referring to the mainland Chinese government.

The legislation contains a clause targeting non-Hongkongers who say or do anything deemed to create hatred and resentment of mainland Chinese authorities.

Mr Chen said the new Taiwan-Hong Kong Office for Exchanges and Services “indicates our goodwill and concern for Hongkongers”. He said anyone in the city could contact the office for help — including with relocation, employment, study and investment. Those seeking to move to Taiwan for political reasons could get advice and start the process for them to travel to the island while they waited for assistance.

Mr Chen said Taipei would treat Hongkongers as a special case and saw the city as part of “one country, one system” with the national security law now in force.

Hours before the law was passed, US Secretary of State Mike Pompeo said the US would stop exporting defence equipment to Hong Kong over security concerns as it no longer saw the financial hub as separate from mainland China. “We can no longer distinguish between the export of controlled items to Hong Kong or to mainland China,” Mr Pompeo said.

On Wednesday, Mr Chen said Taipei was watching developments in Hong Kong before it decided whether to end a law governing their relations. For now, the self-ruled island would make it easier for Hongkongers to relocate to Taiwan, including through investment and skilled employment. SOUTH CHINA MORNING POST