Chief Executive Leung Chun-ying said the majority of Hong Kong people support the "One Country, Two Systems" principle - and only a small minority are advocating "independence" for the special administrative region.
He also dismissed the suggestion by some young people that Hong Kong should prepare for a "second negotiation" for the SAR's future beyond 2047.
"As far as the 'One Country' aspect is concerned, 2047 is a non-event," he said.
In an exclusive interview with China Daily, Leung noted that Article 1 of the Basic Law states that Hong Kong is an inalienable part of China. Therefore, he said, calling for Hong Kong to be detached from the rest of the country is totally unacceptable.
To help people better understand the Basic Law, the government will do more to educate the public to make sure people understand not just one or two articles of the Basic Law, but all its articles, he said.
The SAR's chief executive said that although Hong Kong cherishes freedom of expression, there is no room for "pro-independence" discussions. If students want to discuss this aspect of the Basic Law, teachers should guide such discussions within the context of the law, he added.
"We shouldn't be complacent. If we do not tackle this well, this (separatist idea) could spread," he said.
As to whether the Education Bureau should issue guidelines to schools, he said these are not necessary regarding this simple, clear provision of the Basic Law.
He also commented on a reader's letter to a local newspaper on Sept 15. The reader suggested the possibility of amendments to the Basic Law and changes to Hong Kong's status under a mechanism provided in Article 159 of the Basic Law.
"Paragraph 4 of Article 159 says that no amendment to the Basic Law shall contravene the basic policy of the People's Republic of China regarding Hong Kong. And the basic policy is Hong Kong is an inalienable part of China," Leung added.
Leung also said he was not worried about Hong Kong after 2047.
"My view is that we don't have to change that (capitalist system and way of life), because this 'One Country, Two Systems' serves Hong Kong well today, and in 2047 and thereafter," he said.
Leung noted that the Lands Department is granting leases for 50 years, referring to a land lease granted for a site in Sha Tin. The lease will expire in 2066.