Hong Kong’s democracy advocates called for protests against sweeping national security legislation China introduced Friday. Legislation slated for passage in the National People’s Congress in Beijing by next week would help complete Hong Kong’s obligation to enact laws curbing acts of treason, secession, sedition and subversion, NPC Vice Chairman Wang Chen told lawmakers Friday. The measure would also seek to counter terrorism and foreign interference in Hong Kong. Pro-democracy activists say the move endangers the future of “one country, two systems,” the principle by which the Asian financial hub is overseen by Beijing. The announcement on national security legislation prompted calls for protests and a spike in Hong Kong residents downloading VPN software that helps mask internet usage. U.S. President Donald Trump, when asked about China’s moves, pledged he would respond “very strongly.”