The national security law will specify what politicians can and cannot do during exchanges with foreign dignitaries and government officials while overseas, security secretary John Lee Ka-chiu said yesterday.

Lee said international exchanges are common but some public figures have openly asked foreign governments to impose sanctions on Hong Kong.

"They have also been able to secure appointments with people whom the SAR government officials aren't able to meet," he said.

His comments came after democracy activist and tycoon Jimmy Lai Chee-ying met US vice president Mike Pence and secretary of state Mike Pompeo in July, while political group Demosisto called for sanctions against the mainland and Hong Kong officials during anti-fugitive bill protests.

Hong Kong politicians, especially from the pan-democratic camp, have also traditionally traveled abroad to meet diplomats and government officials.

Lee warned that the upcoming security law being imposed by Beijing on Hong Kong "will clearly stipulate what is allowed during these exchanges and what is not. There will be a clear definition stating what kind of actions during such engagements would breach the law."

However, he dismissed fears that the law would jeopardize freedoms as unfounded, citing the controversy over the joint immigration arrangement at the West Kowloon high-speed rail terminus.

"Even though some people suggested the joint immigration arrangement at the terminus could lead to the abduction of Hong Kong people to the mainland, that clearly did not happen," he said, adding that SAR officials were ready for the law's implementation.

But Bar Association chairman Philip Dykes said Beijing executing jurisdiction over "serious" national security cases appeared to be almost a reversed version of the shelved fugitive bill.

"At the moment it sounds like reverse engineering of the ill-fated extradition bill. Rather than you going to the mainland, the mainland comes to you," Dykes said.

He also said that the security law sounded like "a weird hybrid" between the common law practiced here and mainland law, but stressed he had not seen details of the proposed bill for the legislation.

This came a day after Hong Kong and Macao Affairs Office deputy director Deng Zhonghua said Beijing will retain jurisdiction over cases that severely threatened national security.

Chief Executive Carrie Lam Cheng Yuet-ngor said yesterday that security should override individual freedoms.

"When we look at the International Covenant on Civil and Political Rights, people are entitled to different kinds of rights, but they are all restricted by national security.

Therefore, national security is an issue that can override some of the people's rights and freedoms."

She added that the national security law would not only protect the SAR but also allows it to close national security loopholes.

Law 'draws line on what pan-dems can say abroad'