China on Sunday expanded drastic travel restrictions to contain a viral contagion that has killed 56 people and infected nearly 2,000, as the
United States and
France prepared to evacuate their citizens from a quarantined city at the outbreak's epicentre.
China has locked down the hard-hit province of Hubei in the country's centre and the capital Wuhan in an unprecedented operation affecting tens of millions of people to slow the spread of a respiratory illness that President
Xi Jinping said posed a "grave" threat.
The virus has spread throughout
China and around the world, with cases confirmed in around a dozen other countries as distant as France, Australia and the United States.