A fleet of Chinese warships sailed into Hong Kong's harbour on Friday, in the biggest show of force since the territory's 1997 handover from the UK.
Two destroyers, four frigates and two submarines are visiting
Officials said the eight vessels and 1,500 officers were marking the 55th anniversary of the Chinese army.
But analysts said the visit would also send a signal to Taiwan and pro-independence groups on the island.
The visit also comes as China has ruled out universal suffrage for Hong Kong in its next elections.
Vice admiral Yao Xingyuan, commander of the battle group, hinted at China's hard line on Taiwan when questioned by reporters.
Mr Tung thanked China for its protection
"If necessary, we have the ability to preserve the stability of the Taiwanese political situation," he said.
About 200 members of the PLA marched through Hong Kong's Ngong Shuen Chau naval base, and paraded in front of the biggest vessel berthed there, the Shenzhen destroyer.
Red carpets were rolled out for Hong Kong Chief Executive Tung Chee-hwa and accompanying Chinese and Hong Kong officials and naval officers.
Patriotic music played and seven golden Chinese lions performed an acrobatic display in front of the Shenzhen.
"We thank you for your strong support to us and for ensuring the long-term prosperity of Hong Kong," Mr Tung, hand-picked by Beijing as Hong Kong's leader, told the troops.
Hong Kong's democracy groups are still reeling from China's announcement last week that it would not allow the territory's citizens to choose their own leader in 2007, because it could result in social and economic instability.
It said that Hong Kong would be allowed to make changes to its electoral methods, but only gradually.