Hundreds of members of China’s paramilitary People’s Armed Police carried out military exercises at a sports stadium on the Hong Kong border on Thursday as the U.S. State Department expressed “deep concern” over reports that the Chinese military might march on Hong Kong. The escalation comes as protests have largely abated at Hong Kong International Airport after days of clashes between pro-democracy protesters and police. President Donald Trump, who has so far remained quiet on China’s handling of the matter, suggested in a tweet early Thursday that he and the Chinese leader should meet. “I have ZERO doubt that if President Xi wants to quickly and humanely solve the Hong Kong problem, he can do it,” Trump tweeted. “Personal meeting?” Politico reported Wednesday that the president’s top national-security hands had been unsuccessfully begging him to show public support for Hong Kong’s pro-democracy forces.