Li, who was brought to court by a fleet of police vehicles this afternoon, was one of the eight Hongkongers sent back to Hong Kong after completing jail terms on the mainland for illegally crossing the border while attempting to flee the city for Taiwan.
The eight were among the 12 local fugitives intercepted at sea by the Chinese coastguard during a failed escape bid last year.
The 30-year-old was charged on March 24 at West Kowloon Magistrates' Court. However, Li did not attend court on that occasion as he was still in quarantine, and he was not represented by a lawyer at the time.
Wearing a white shirt and holding a stack of documents to his chest, Li said he understood the charges. He did not apply for bail, nor did he ask to be brought to the court again in eight days to review his decision.
Chief Magistrate Victor So Wai-tak, a magistrate designated to handle national security cases, adjourned the case to May 18.
Several countries, including France, have suspended flights to and from Brazil due to fears over the more contagious coronavirus variant spreading there.