WHO Hopes ‘Aggressive’ Surveillance Will Contain Coronavirus Outbreak – Official

"We commend the move towards more aggressive, targeted surveillance and we hope that that will lead to the kind of control measures that will help push this virus back", Mike Ryan told reporters.

He warned countries against adopting tit-for-tat travel restrictions after South Korea said it would respond with countermeasures to Japan’s decision to quarantine its visitors starting Monday.

"We have been pretty clear on the issue of travel restrictions for a long time: they should be very carefully considered, they should be public health evidence-driven, they should be of short duration", he said.

Ryan admitted that there was a long history of countries trading travel bans, but the practice has been largely abandoned after WHO began challenging nations on the measures they took to contain epidemics.