The revelation that one of the hospital nurses was cleared to fly on a commercial airline the day before she was diagnosed raised new alarms about the American response to the Ebola outbreak in West Africa.
The death toll is expected to climb above 4,500 in Africa, all but a few within Liberia, Sierra Leone and New Guinea, the World Health Organisation said.
The two nurses, Pham and Amber Joy Vinson, had been involved in providing care to Thomas Duncan, who died of Ebola last week.
In Washington, President Barack Obama directed his administration to respond in a "much more aggressive way" to the threat and, for the second day in a row, canceled his out-of-town trips to stay in Washington and monitor the Ebola response.
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Today, Chinese President Xi Jinping pledged continued support but made no specific new aid offers. China last month pledged USD 33 million in assistance and dispatched doctors and medical supplies.
In a hearing on Capitol Hill, the chairman of a House committee cited "demonstrated failures" in the government's response. Rep Tim Murphy of Pennsylvania said the "trust and credibility of the administration and government are waning as the American public loses confidence each day."