China is engaged in a massive nuclear weapons buildup that includes hundreds of new strategic missiles, and Chinese President Xi Jinping is preparing the military to retake Taiwan, USA’s most senior intelligence official told Congress on 8 March. Avril Haines, director of national intelligence, disclosed new information on threats from China and dangers posed by Russia, North Korea and Iran at the annual briefing on threats to US security around the globe. China’s military buildup includes the largest ever nuclear force expansion and arsenal diversification in its history, and there were 39 incursions Into Taiwan's airspace by fighter planes in one day. The Pentagon is warning that China is preparing for a military campaign, so it is sending new sales of advanced-grade military drones to Taiwan.