Taiwan's Presidential Office conducted its first ever tabletop exercise simulating a military escalation with China, several officials briefed on the matter said, at a time when the island is facing renewed Chinese military threats. China has in recent years stepped up military threats, including the large massing of naval forces this month and daily military activities close to democratically Taiwan, which Beijing claims as its own over Taipei's rejection. The war game held inside the Presidential Office in Taipei was led by Vice President Hsiao Bi-khim and National Security Council Secretary-general Joseph Wu, the officials familiar with the meeting told Reuters.