Donald Trump's announcement of unprecedented new measures to tackle the coronavirus prompted shock and criticism from former officials and commentators on Wednesday evening.
In an address to the nation from the Oval Office that was marked by missteps, Mr Trump declared severe restrictions on travel between the US and Europe for 30 days - with the exception of the UK and Ireland.
The president, who has faced criticism for not moving fast enough to contain the public health crisis, described the measures as "the most aggressive and comprehensive effort to confront a foreign virus in modern history."
Susan Rice, who played a key role in the Obama administration's response to the Ebola crisis in her role as national security advisor, was among the first to tweet her reaction, saying only: "OMG".
One of Obama's top foreign policy advisers, Ben Rhodes, described the president's speech and his handling of the crisis as a "dystopian nightmare".
"Important and aggressive actions by @ R ealDonaldTrump to protect the American people. Compassionate relief for those who need it here with a commonsense approach to preventing further and unnecessary spread of the Wuhan coronavirus. Well done," he wrote on Twitter.