Just days into the new year, Chinese President Xi Jinping has ordered his country's military to improve its combat readiness and prepare for the possibility of war while also warning of "unprecedented risks and challenges" in 2019.

Xi's warning comes amid territorial disputes in the South and East China seas and rising tensions with the United States over issues ranging from trade to Taiwan.

The Chinese president told a meeting Friday in Beijing of the Central Military Commission, the country's top military authority, that the armed forces must devise strategies in the coming year and take on more responsibilities in readying for and waging war.