The world still has a "long, long way to go" to bring the COVID-19 pandemic under control, the World Health Organization's top emergencies expert warned on Wednesday, as countries around the globe move to gradually ease restrictions aimed at curbing the spread of the disease.

In a WHO briefing, the organization's head of emergencies programme, Dr Michael Ryan, said risks from COVID-19 remained high at "national, regional and global levels”.

"What we all fear is a vicious cycle of public health and economic disasters if lockdowns are eased without the ability to detect fresh outbreaks," said Dr Ryan.

He added that "very significant control" of the virus was required in order to lower the current risk assessment.

Many governments have rolled out plans to restore normal life while still trying to contain the virus which has infected close to 4.3 million people and killed more than 294,000, according to data from the U.S.-based Johns Hopkins University.

Most of those countries have seen their economies take a battering due to the restrictions placed to curtail the spread of COVID-19.

The European Union on Wednesday pushed for a gradual reopening of borders within the bloc, saying it was not too late to salvage some of the summer tourist season while keeping people safe.