for us as an effective movement for us to force the government to reply to our demands. >> reporter: beijing has called this terrorism and tonight is sending a message. chinese state-owned media showing forces assembling near the border with hong kong for what they say are exercises. president trump today asked about the situation. >> i hope it works out peacefully and i hope nobody gets hurt and nobody gets killed. >> reporter: later, ominously tweeting, the chinese government is moving troops to the border with hong kong. everybody should be calm and safe. >> ian, president trump responding as you reported. and tonight there's real debate over what role the u.s. should play if any as the protesters push for democracy. >> reporter: that's right. on the one hand, the president being accused of pulling his punches. on the other, tweeting he's being blamed for the problems in hong kong. it's not clear who he thinks is blaming him. if it's the chinese government, they certainly criticize america for backing the