TAIPEI (BLOOMBERG) - Former Taiwanese President Ma Ying-jeou, barred from travelling to Hong Kong to address a journalists' group, opened a video message to the gathering with a dig at his successor's claim that security concerns necessitated the move.

"I didn't know that Hong Kong is such a dangerous place," Mr Ma told the Society of Publishers in Asia's annual awards gala on June 15. "Ladies and gentlemen, you better watch out."

The joke and another quip about taking care not to "leak any more state secrets" were all the criticism the former Kuomintang leader chose to levy against President Tsai Ing-wen over the cancelled trip, which would have made him the most senior Taiwanese figure to visit Hong Kong since the Chinese civil war ended in 1949.

While Mr Ma called the decision "quite curious", he didn't repeat an earlier statement from his office describing it as disrespectful and potentially damaging to Taiwan's reputation.

Mr Ma was the first former president denied travel under the Classified National Security Information Protection Act of 2003, which restricts trips by former top officials for up to three years after they leave office, Central News Agency (CNA) said.

Ms Tsai's office said it rejected Mr Ma's request because Hong Kong was a "highly sensitive region". More time was needed to assess what information the two-term leader had and how to secure such a trip, it said.

Hong Kong returned to Chinese rule in 1997, although the former British colony has guaranteed freedom of expression and controls its own legal and immigration systems.

Mr Ma, who was born in the city, spent much of the video expounding its unique role in Chinese history.

Mr Alex Huang, a spokesman for Taiwan's Presidential Office, didn't answer two calls to his mobile phone seeking comment.

'ONE-CHINA PRINCIPLE'

He also reiterated the need for talks between Beijing and Taipei based on the "one China" principle, which underpinned improved relations during Mr Ma's eight years as president.

Under it, both sides agree there's one China, even if they disagree on what that means.

"For us, of course, 'one China' means the Republic of China," Mr Ma said, referring to Taiwan's official name.

Ms Tsai's Democratic Progressive Party officially supports independence and Beijing has warned her refusal to accept the framework could jeopardise relations. Taiwan's constitution, Mr Ma said in the video address, also prohibits the establishment of an independent Taiwan.

In a brief question session, the former leader also spoke about the prospect for democracy in China. He said that tolerance for dissent could be found in China's ancient history and said Beijing's framing of tolerance as a Western concept wasn't accurate.

Taiwan shares China's claim to more than 80 per cent of the South China Sea, where territorial disputes with neighbouring nations have been an increased source of international tension.

In response to a question, Mr Ma called on claimant nations to jointly develop resources, a position he advocated while in office.

"This is probably the only way out," he said. "If the confrontation or escalation of tensions continues, there will be no solution at all."