HONG KONG (Reuters) - Hong Kong braced for more mass protests over the weekend, even as China warned it could use its power to quell demonstrations and U.S. President Donald Trump urged his Chinese counterpart, Xi Jinping, to meet with the protesters to defuse weeks of tensions.

Hundreds of China's People's Armed Police (PAP) on Thursday conducted exercises at a sports stadium in Shenzhen that borders Hong Kong a day after the U.S. State Department said it was "deeply concerned" about the movements, which have prompted worries that the troops could be used to break up protests.